Cheating by my husband, manipulation asking for money, mental and emotional harassment

Hello, I got married to my husband 3 years ago and since marriage he was in financial debt, I always helped him whenever he asked for, he always used to lie and when caught act as if nothing happened that started having issues among us. There was mental and emotional harassment along with domestic violence.Last year in June I got a government job for which I had to be in another town but even when I am staying with him, he started having an affair and things became worse when I was in another town and he was intimate with other woman physically, when I caught him, he pleaded for forgiveness, ask for another chance and I gave the same since it was a love marriage but things worsen and gradually he started harrasing me mentally and emotionally , that compelled me to attempt suicide many times. But since he always manipulated me and told me that he wants a baby, I agreed but since I have been pregnant, his harassment worsened, he keeps asking for money from me and even my family members by blackmailing them emotionally and if I don't give him money, his behavior turn even worse.. I am currently five months pregnant but neither he is taking any care nor he is accountable for the mental trauma he has given me which sometimes tempt me to attempt suicide even in my pregnancy. If my parents try to talk, he abuses them too but not in front of them, in front of me that causes more mental stress even in pregnancy. I informed his parents but they act numb and his sister accused me falsely. I want to take legal action against him. How can I punish him and what will be the sections I can apply? He is a government employee and I also need alimony along with unborn child support