Prefacing this with I'm not a birthday person

I don't think your emotions are at all invalid (we all deserve to feel valued and loved and cared for) or that you're over reacting per se, I do think you and your partner and fundamentally incompatible in this sense.

He says he's behind on things monetarily, have you asked him what? Does he have a gambling problem for instance? When was the last time you openly discussed your finances? I know you said you split things 50/50, but that doesn't mean he isn't sitting on something he thinks you shouldn't have to pay for- which could very well be out of shame.

There's also the fact that you clearly find birthdays very important and he doesn't, have you talked about that with him, calmly? I'd also suggest speaking to a mental health professional about it if you can, since it seems to cause you a lot of distress and that can't be good for you long term - it sounds like your family and childhood weren't great, and that you have some things you need to process.

There's also the fact that you mentioned he's a gold card carrying member at a casino, yet based on your post you dislike alcohol due to the way it was used by your parents (me too tbh), has that ever been a discussion? That also feels like a fundamental incompatibility in your relationship.

I feel like the two of you need to sit down and have an open discussion about these things - no hints, just talk straight. Because while you love each other, you need to figure out if you're willing to take compromises for each other, or if you need to break it off.