You don't say anything specific about what he's not doing to "support you." Through your own words, you make it sound like you're being overly selfish. Do you think the pregnancy hormones are exacerbating things? Are you sure you're not asking or expecting too much from him? His father is dying. He has a 2 year old that he doesn't see much right now. He doesn't physically see his wife all that much. His wife is pregnant and angry with him. He is serving his country, sacrificing his personal life for his country being deployed all the time. He may have seen war. You don't live together (not anyone's fault, you're both doing good things).
He's going through a lot right now, too, don't forget that. Are you supporting him the way he needs you to?
I think you both need to be more supportive and understanding of each other. Threatening divorce doesn't help anything. I know you probably said it out of anger, and he responded out of anger, but probably neither of you meant it or wants that.
I think you should seek marriage counselling. There was a time when you loved each other enough to marry and to have a child. For the sake of that love, and that child, you MUST work on the marriage. Marriage is very hard work. Give it your all, and if after a year or so of counselling and getting your lives back to normal (living together, at least) you find you still can't make it work, then separate. But don't throw in the towel in the midst of crisis. Crisis is hard on ANY marriage. Its how you as a couple work through it that makes or breaks that marriage.
I'm sorry you're going through all this. Hang in there. I hope it works out for you.
Re-reading your post and your additional details. You are so mad you want an abortion? You blocked his phone number?
That is very immature.
He is the father your son. You cannot cut him off. He has rights. How is he supposed to contact you regarding his son? If he can't get a hold of you and you have his son, he can call the police. That looks very bad on you if things go sour. Don't be stupid. You don't have to talk to him if you don't want to, just don't answer the call or talk through his or your family, but you need to keep the lines of communication open for the sake of your son (and future child!).