Help I need advice

So my boyfriend just found his adoptive mom and siblings. He’s been so excited and I really want to be excited with him. However, I’m really scared that he’s going to get hurt. He is sensitive and has ADHD. Ever since he’s found them he seems to be happy. Whenever he’s with me it seems that I bring him down... well his mood. He says I’m always fussing at him. I’m worried that he’s going to leave me if I’m not supportive, which I really am trying to be. Every time I try to talk to him he kind of snaps at me. We hardly talk anymore, it seems like he’s becoming more distant. Please tell me some good advice because I’m emotionally hurting.