How to resolve conflicts when moving in

Hi everyone, long story short my BD and I are back together after 5 years (we were HS sweethearts) so we’re still young, I basically live with him, he always wants me with him so we had a talk and both came to terms that I’m moving in. (He lives with his siblings) when we get into disagreements/ conflicts he doesn’t understand how uncomfortable I feel there. There’s no where for me to go to cool down. So I’ve been having to come back to my grandmas (I was staying before we made that decision to move in) I feel so stressed, I can’t stop crying because I don’t think he understands how draining this is… having to leave when there’s a conflict because I do not want his family involved. I’m starting to second guess moving in when this is the “solution” I can’t keep doing this because we have disagreements. I feel so depressed because I’m constantly going back and forth with our daughter.

Please (this is a first I live with a man) any tips/ opinions…