I got myself a birthday present and I'm going to thank myself to my husband's face.
Is this something that your husband deserves?
He forgot all about my birthday!
I get that you are upset, but you should try not to be spiteful. I know he forgot to get you a present but it can be hurtful to throw it in his face like that.
He can leave and send me a postcard.
Your anger is completely understandable but ultimately your husband didn't mean to forget and it would be a good thing if you forgave him. I'm sure he feels guilty and won't do it again. As such, it's probably best to move on from the mistake for the sake of everyone.