You’re in a tough situation because you got pregnant so quickly in a relationship — in fact, after only 3 months of dating. Now you’re living together after only 10 months together, and you have 4 other children from previous relationships. Whew! That’s a lot for anyone, let alone someone who’s only 22 years old.
My suggestion to you is to try and make this work and create a family together. If all you’re doing is fighting about petty things, one of you is going to have to diffuse the fighting. (It always has to start with one person.) My suggestion is that you take the high road on this one. Rather than act defensively with him, and argue back, when he criticizes you, stop and take a breath. Then smile at him and sigh, and tell him he’s right. You wish you could do more around the house — and that, in fact, you’re going to try. Then do it. Do try to do more around the house. (He’s not asking you to mow the lawn or shovel the snow while pregnant.)
When he tells you that you need to grow up and learn to live on your own, again, stop and take a breath. Tell him that he’s probably right, but that the reality is here you are with a baby to be born in 4 months, a child from a previous relationship, and a possible step-mother job for his 4 kids! You want to please him, and make a family with him so that you all have a home together, and that you love him.
I know you’re pregnant and under a lot of stress right now. So is he. Be kind to each other. Find the good things about each other. Give each other little love notes and presents. Try to keep your sex life going, and do your best to turn things around.
And in answer to your question, “Should it be this hard?” Yes. If you’re 5 months pregnant after knowing your boyfriend for only 10 months, and have 4 other kids between you, the answer is yes. It’s supposed to be this hard. So don’t complain — do the work, and get through the difficult years ahead of you. Together.