Why do I feel such strong depressive thoughts at the end of a good night out?

For context I’m someone who WAS extremely depressed and suicidal ending around six months ago. Last night me and some friends I haven’t seen in years went out into town. Great night, was drinking from about 5pm until 4am this morning. But when I got home, I was so depressed, cried on the floor and even SHed and (stupidly) texted people about it then went to bed. Woke up today with the worst hangxiety ever and regretting that last part.

I still think of it as a good night out despite how it ended but man am I confused. I have no depressing feelings now. I don’t understand what caused that to happen, and if I should still consider it a good night out or not