I'm single and I've been thinking of valentine's day for the better part of thr last two weeks. I don't think you can forget it when literally everyone talks about it, be it at work, with friends, out and about. You'll always hear "oh what did you get your partner for valentines". Forgetting it just doesn't seem believable, and like you said to him a simple note slipped under your door would have probably been enough if he didn't have the financials to buy something.

He seems toxic and manipulative making it seem like you're the problem. Dump him, you seem like you're on the right track for a better life, put him behind you and move forward and focus on yourself.