Relationship

My boyfriend and I have been together for 6 months now and he sending so many mixed signals. He’ll talk and laugh with other girls, which doesn’t bother me considering I have guy friends that I can joke around with, but he doesn’t even do it with me. I can joke around with him and he’ll just be serious and not even seem to care. So assuming he’s upset I just give him his space (not ignore him) and he starts trying to get my attention and get me to love on him. He is always acting so upset or serious and I’ve feel like I’ve tried everything from asking him what’s up to letting him be to just crying right there in front of him bc I feel so overwhelmed from trying. And overwhelmed from seeing him so happy talking to other people but not when he talks me. And he always says he doesn’t understand what’s wrong, always. I just don’t even know what to say to him anymore and it’s not like our relationship is dead. We still have those moments when we love each other, they’re just always when we’re alone. I’m so confused with all of this.