Let us come to a logical conclusion by giving some positive advice.
The author herself agrees that she is too sensitive and let us not make her more sensitive to the issue.
@Author: 1. If you have not filed complaint under 498a, please do not resort to it as in your entire query there is no dowry harrassment. Supreme Court came heavily recently on misuse of this section.
2. It is just 3 years old marriage and you have kid and living separately for more than one andhalf years. Marriage is such an event in the life you can not go back that easily unless you have no option to live respectfully. What is the root cause for this trouble? Why did he balem you on the grounds of chastity? What is your role in creating doubt in his mind to this aspect. Nowadays, younger generation do not attach much importance to it, but at least they expect, once married the spouse will confine to him/her. Some people are very sensitive on this issue. What is your role in this particular aspect.
3. Already some panchayats are conducted. You have not given particulars of outcome.
4. Your husband does not have father. You did not say anything about his mother. You are pointing out at his brothers-in-law. Where do they stay? Where your does your stay? Where you do stay?
5. You are not in a position to pull-on with him bearing all the abusives on you, at the same time you want that your son should not loose his father. How this is possible unless you reconcile yourself. His offer appears to be reasonable - that come back and join - it is his conjugal right - otherwise ready for MCD - this is also reasonable - so that both of you can come out of marital tie and live as you wish.
6. Decide yourself. He will not agree for any treatment. Even if it is a fact that he is suffering from some psychic problem, at this stage he will not co-operate with you for treatment. Living with him for some time and share love and affection, will make him to agree for treatment. You should have lot of patience for this. You can not afford to be too sensitive.
7. What about your parents? You did not say anything about them.
Final decision is yours - either to reoncile and live with him for some time so that you can expect some change in him - at the same time some change in you also - second is go for MCD. Even if you go for MCD, with a child in your arms who will welcome you in his life? It is not that easy. There also you can find partner if you are not too sensitive and you are loveable women. You can try with your husband with love and affection.