What do I do if my husband is forcing me to have an abortion or we will divorce and he will take my daughter from me?

My husband went to work away and while he was away, he had an affair and in my own stupidity I had an affair as "payback" and I fell pregnant. Now my husband is threatening me that I should get an abortion or we will get divorced. He will make sure I lose my daughter. A few years ago, I gave him an anti- depressant for about 2 weeks without his permission to see if he would feel better so that I can get him to get his own description. A few months later, the doctor prescribed the exact same anti- depressant. It was a mistake and I did not know the consequences. He says he will use this against me in court and get me locked up for some kind of murder charge. I do not believe in abortion and I have offered adoption as a solution. Can my husband do this? I am scared and do not know what to do. I fear I might lose my daughter even though I have been basically looking after her. I feel that even though we are married, I am a single parent. I am from South Africa but this is the only free online help I could find.