We praise Allah for your recovery from waswaas, and we ask Him, may He be glorified, to complete His blessings and grace to you.
Social phobia is a kind of psychological disorder, that has its causes and ways of treating it; it varies in its degree and intensity.
What this suitor has mentioned about difficulty in being alone with a woman and so on, all comes under the heading of the symptoms of this phobia.
Our advice to you is not to go ahead and marry this suitor until he has recovered from this illness, or it is apparent that he is only suffering mildly from it. This can be found out by asking his friends and neighbours, and the people at his mosque. Your guardian should ask about him and find out about that, and also ask this suitor about the stages of this illness and his treatment, and he should also check with the doctor who is in charge of his treatment, if possible.
It is important that his looking to get married be based on his desire and need, and it should not be in response to pressure from his family or anyone else.
We ask Allah to decree happiness, guidance and well-being for you.
And Allah knows best.