Consult your doctor. For one, if your having domestic issues you need to get away from that, the stress is not good for you or your baby. I was in a relationship with my second son and he was verbally and mentally abusive (only while I was pregnant) and my son was born 5 weeks early. I can't say that's why he was born early, but I'm sure the emotional stress contributed a little. I don't know your situations specifics but 'domestic problems' to me only mean one thing.
Two, you NEED to eat more than that. Your baby survives off the food you eat, it gets all its nutrients ect from you. Even if you don't feel hungry, eat snacks, couple carrots or something like that.
good luck, I hope everything works out for you.