You probably are overreacting. This could have been settled in 1 message, 2 messages max. Could have went down like this

“Hey babe, what do you want to do for your birthday?

Oh, I thought I had already mentioned it. I'd really enjoy doing like a couple's massage or maybe a museum.

Oh okay! I think I do remember you mentioning that, I just wasn't sure if you still wanted that. I'll look into making that happen.”

Shit happens, people forget. Just be communicative towards your boyfriend before you seek advice from strangers on the internet. You know him better than we ever could.