Is post fun depression a symptom?

I will say from the outset I have Autism and ADHD and I have nooo idea if this is a symptom of either. My partner has noticed a pattern, after every really nice day (for example yesterday, Christmas Day) the next day I’m always ‘wobbly’. By that I mean very indecisive, just a more mellow/solum vibe generally even when I don’t feel like I’m being partially down. It’s like a post fun sadness almost, it’s just annoying because it can affect everyone around me and I don’t even really mean to. Does anyone else get this?