Choosing a Thanksgiving 😫

So I RSVP'D to my boyfriend's family Thanksgiving because my family usually doesn't do a big Thanksgiving. Well this year my family decided to do a Thanksgiving after I had committed to going to his already. I cant attend both because my boyfriend and I are somewhat long distance (an hour and a half apart) so the times conflict. I've always felt very guilty making choices like this because I never want anyone to feel left out. I will feel guilty if i dont see my grandma or my baby cousin in particular and my mother is saying I will regret not coming to Thanksgiving and I'll feel guilty about it later because that's just how I am. She said "it's not like you're engaged or anything" so I shouldn't have to choose between my family and his. I was excited about mingling with his family though because we've been together almost 8 months and I feel that its important. I'm not sure what to do. He told me its family and he understands if I want to back out of his but I would feel rude after already telling his uncle I was attending (which he had to know by a specific date which was a like a week ago). I was also excited about it. Now I'm just afraid that if I go to his I'll be thinking about how awful I feel for missing my family's the whole time. I know I'm making a bigger deal out of it than this is but I have a really hard time with anxiety. What are your opinions?