Am I right for being annoyed about this

Nat

I am in uni studying fashion and I have a summer project . I have to go to museums and exhibitions. I asked my boyfriend would you come with me if I booked this . He said yeah and I said definitely sure u can and want to come . And he was sure he would come. I paid for both tickets because it feels right because it’s something for me like he’s just there for me really it’s not something he’s interested in and it wouldn’t be fair.

The date has come around and it’s a couple days before and he said to me I can’t come with u I have to do my own uni work you will have to find a friend to go with I’m sorry. I tried to just be understanding and said yeah okay that’s fine like and I messaged around but no one can come with me my family are working my friends are busy.

I say il go on my own

It’s the night before and I’m looking for trains and some trains are on strike so there’s like some cancelled trains and problems I’m a little worried and stuff and he’s really not said much on it even though he knows I’m not happy about if I feel like he’s not being considerate. I’ve been patient with his uni work I’ve helped him with it and there are other days this week he can do his work. He can’t just come with me its in the after noon he could still work befor and after it . I’ve baught the ticket and he knows I can’t get a refund and hasn’t even considered to give me the money for it .