Sometimes the shaytaan tempts me and makes me do what is called masturbation, which leads me to stop praying for five days or two days or more or less according to the circumstances. What do I have to do? Do I have to repeat the obligatory prayers I missed? Or can I do naafil prayers to expiate for that?.
You have to hasten to give up that bad habit, which is contrary to dignity and chivalry. In the answer to question number 329 we have quoted the evidence for it being haraam.
You also have to repent for missing the prayers, because not praying is a serious major sin; in fact many scholars say that it is kufr.
Repentance includes giving up the sin, regretting what one has done and resolving not to go back to that haraam deed.
Do a lot of naafil prayers, to make up for the prayers that you have missed, because the Prophet (blessings and peace of Allah be upon him) said: “The first deed for which the people will be brought to account on the Day of Resurrection will be prayer. Our Lord will say to His angels, although He knows best: ‘Look at the prayer of My slave and see whether it is complete or lacking.’ If it is complete, it will be recorded for him as being complete, and if anything is lacking from it, He will say: ‘Look and see whether My slave has any involuntary (prayers to his credit).’ If he has involuntary (prayers to his credit), He will say: ‘Complete the obligatory prayers for My slave from his voluntary prayers.’ Then other deeds will be judged in the same manner” Narrated by Abu Dawood (864).
We ask Allah to forgive us, you and all the Muslims, and to grant us all well being and to make us all steadfast.
And Allah knows best.