Plz help.

Not like your neurotypical peers, you mean? It is rough, and speaking as someone with a half-lifetime of experience, there are still times when it kneecaps me with the feeling of being an alien.
Also, the depressive effect of social media is pretty well-documented. If you're feeling worse after spending a chunk of time on TikTok, that may be a reflection on TikTok, not you or your situation. It's always worth reflecting on how things make you feel, especially if you're on the spectrum and they may not affect you the way they do other people.

I'd say watching Tik-Toks at all will keep you from understanding stuff

I would take autistic/ neurodivergent content on tik-tok wth a grain of salt, as quite a few people will exaggerate or straight up lie about their condition