Your question, may Allaah bless you, raises a number of issues, some of which are mentioned in the question and some to which attention must be drawn.
One of the issues raised in the question is that you ask about having your father’s agreement. You have to realize that sharee’ah stipulates that there must be a wali (guardian) in order for the marriage contract to be valid, because there is a great deal of evidence to that effect, such as the hadeeth in which the Prophet (peace and blessings of Allaah be upon him) said: “There is no (valid) nikaah (marriage) without a wali (guardian).” (Narrated by al-Tirmidhi, 1101; Abu Dawood, 2085; Ibn Maajah, 1881. It is saheeh as stated in Irwa’ al-Ghaleel by al-Albaani, 6/235).
There is great wisdom in what Allaah has prescribed by stipulating that there must be a wali. For example, the basic principle is that men are more perfect in reason, and have more understanding of where interests lie and they have more insight into the circumstances of men and what is suitable for a woman, and they are more able to take decisions, especially since a woman may be overwhelmed and swayed by her emotions. If we assume that there is some fault in the wali that make him unqualified to take responsibility for the woman under his guardianship, or he is preventing her from getting married to a compatible man with no legitimate shar’i reason, then guardianship passes to the next in line, for example from the father to the grandfather. (For more detailed information in this issue, please see Question no. 7193).
With regard to his family’s approval, this is not a necessary condition for the marriage to be valid, because the man is his own wali, so his marriage does not require the agreement of his family. They have no right to prevent him from marrying for no legitimate shar’i reason. His concern about their approval, especially his parents, is a good thing, and he may gain their approval by treating his parents well and doing whatever he can to make them agree to his choice, and seeking the help of Allaah in that by making du’aa’, debating with them in a polite manner, and seeking to convince them in gentle ways.
We are happy to congratulate you for Allaah’s blessing in enabling you to wear correct Islamic hijaab and to memorize His Holy Book. We ask Allaah to make us and you among those who act in accordance with it.
We would like to draw your attention to what you mention in your question about “falling deeply in love”, “we love one another very much”, “he gives us love” and “My daughter and I are in great need of his love and care towards us”. You have to realize that both Muslim men and Muslim woman must protect themselves against the things that may lead to forming an emotional attachment to someone who is not a spouse, whilst accepting that people may not be able to have full control over their emotions. But there are many things that a person may do that may lead to such attachments, and these are the things which are forbidden. For example, chat between a man and woman to converse, which may provoke these emotions and desires. Repeated visits are also forbidden. The Prophet (peace and blessings of Allaah be upon him) said: “Beware of entering upon women.” (Narrated by al-Bukhaari, 4934; Muslim, 2172). These things are forbidden in order to close the door to things that may develop from them. The wisdom behind this is that it prevents the formation of an emotional attachment to a person whom it may not be easy to marry, which would result in heartache for both parties, examples of which are well known, both ancient and modern. This may also distract the heart from things which are obligatory, namely loving and obeying Allaah. Ibn al-Qayyim spoke of the damage caused by such attachments in some of his books, such as al-Daa’ wa’l-Dawa’, and Ighaathat al-Lahfaan, which are worth reading. You can also refer to Question no. 9465.
What we advise you to do, since Allaah has enabled you to wear the hijaab, is to complete the hijaab of cloth with the hijaab of the heart by taking an impartial look at the relationship you have with him now, and keeping away from everything that could make you form an emotional attachment to him, such as speaking to him, letting him visit you and your daughter, etc, which are haraam or nearly haraam. He, since according to what you say he is religious, should keep even further away from such things, lest the Shaytaan intervene between the two of you.
With regard to his kindness towards your daughter, we ask Allaah to reward him for that, but that should not result in any haraam action, such as his entering upon you when there is no one else apart from your daughter with you, because her being with you does not cancel out the fact that you are alone together in the haraam way which the Prophet (peace and blessings of Allaah be upon him) warned against when he said: “No man is alone with a (non-mahram) woman but the Shaytaan is the third one present.” (Narrated by Ahmad and by al-Tirmidhi in his Sunan, 2091; see also Saheeh al-Jaami’, 2546). See also Question no. 2986.
With regard to your hopes for marriage to him, we advise you to do a number of things:
1.Pray istikhaarah a great deal until your Lord chooses for you that which is in your best interests in this world and in the Hereafter. To learn how to pray istikhaarah, please see question no. 2217.
2.Avoid the things mentioned here that may create an emotional attachment, because the most important means of attaining what one wants is adhering to sharee’ah and keeping within its limits.
3.Strive to reduce the intensity of love referred to in the question by understanding the dangers involved, and focus your heart on Allaah and on pondering the meanings of His words with which Allaah has adorned your heart by enabling you to memorize them.
4.Try to get closer to your father, treat him kindly and strive to honour him. Perhaps that will soften his heart and make him want to do that which will bring you happiness and stability.
5.Apologize to the man’s family and interact with them in a way that will show them that you regret what you did to them. Perhaps Allaah will open their hearts to this marriage, which will make it easier for your father to accept the idea.
6.Prepare yourself to accept what Allaah has decreed – even if it is not what you would like – by being prepared for the worst case scenario, such as not being able to get married at all, because when you accept the worst case scenario, it loses its power to shock you, which may lead to frustration or loss of faith, or thinking negatively of Allaah and His wisdom.
7.Strive to give this orphan whom Allaah has placed in your care an Islamic upbringing, and treat her kindly, for in bringing up and sponsoring an orphan there is great reward which may be the means of bringing blessings to you and divine help in all your affairs.
We ask Allaah to perfect His blessings upon you and to make faith steadfast in your heart and to help you to do all that is good. May He make this marriage easy if it is good for both of you, and may He guide us all to the straight path. May Allaah send blessings and peace upon our Prophet Muhammad and upon his family.