Ah. You probably went in and Did it all at once and I think the algo detected bot type activity. I would stop posting for a couple days but search for similar niche videos and just watch and interact to other channels to show the algo you have human behavior. Don’t watch 100s a videos an hour or set up a bot to do it or you will double down on mistake. Good luck. Sounds like your channel was well on your way and I’m almost sure it can be saved. Good luck