Hi, now this I can most definitely relate to. My husband is not big on remembering my birthday, especially when we were first married which was 23 years ago. Granted, we got married young, he was 24 and I was 20. So, now when I look back I just chalk it up to youth. It used to bother me, no birthday gift, no Valentine etc., but now I don't care so much because I know he doesn't do it on purpose, and I know he loves me regardless. In recent years I have bought or made my own cake, or bought myself a new pair of shoes or whatever, because I figure it's my birthday so I treat myself. And I don't really want a big to-do so it's fine with me if I only get a card from him.
I'm not sure if it is anxiety or just feeling left out or forgotten, which like I said, I definitely have been there before, so I know how you feel.
My advice is when your birthday rolls around do something special for yourself, even if others forget, you'll have a good day regardless :)