What the hell should I be thinking or am I just paranoid?

Usually my boyfriend would be more attentive to my feelings. Lately he is just focused on his own. We tried to go to foxwoods and he ate some of my edibles. We ate at an old fashioned diner and nostalgic music started playing and it made him upset because it reminded him of his grandfather that passed away six months ago. Then he became very irrational with every movement and became upset with everything I did until we left and he yelled at me saying I only think of myself and not how he was feeling. He said I needed a therapist and I have no friends. Until he got weed that suppressed his negative emotions and calmed down. The next day he only worked a few hours. Then wanted to go to a friend's (girl) house with her boyfriend there. And he hung out for several hours until 3am. No notifications and barely communicated with me. I have been uncomfortable with her for a while because she's his ex from years ago. But she has a boyfriend there from another state that stays over. Regardless the next morning my boyfriend is more attentive to my emotions and my needs. He barely gets upset anymore and pats my shoulder. He asks me what's wrong and talks very genuine. It's very abnormal after two years of living together. I shouldn't think that anything happened with them last night. I want to stop thinking he slept with her. Honestly though it's very off-putting and if I mention it to him I feel like he will be offended even if he is being genuine to my feelings. Although he has always made it about himself and talks about himself. What's with the sudden change? Is it that he needed friends to be with or did he cheat? He barely was speaking to me all last night. He did ask me how I was doing and all when it got late. He is poly. But he did also say sleeping with her would ruin their relationship but they connect so well whenever they talk with each other. I can not feel comfortable with this. Should I just let it be?

What the hell should I be thinking or am I just paranoid?
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