Firstly, I'd say go ahead and unfollow anyone problematic who causes you anxiety if you haven't already done so. You won't miss them, and you'll be better for it.
Secondly, I'm not sure what kind of phone you have, but there are apps that will lock down your usage and give you all sorts of disincentives to keep using destructive apps. They're usually called Screen Time Apps. Here's an overview:
https://www.digitaltrends.com/mobile/best-apps-for-limiting-your-screen-time/Lastly, I don't know if this one will work for you, but it does for me, so I'll share it just in case. Sometimes I have a craving for drama. I don't know why, but maybe it's the same reason people watch stuff like reality TV or soap operas, only I prefer that mine involves real people, and usually involves being online. So I enjoy watching drama recaps on Youtube, where they go talk about low stakes silliness in an essay format for an hour or two. It gets that itch for me, but it's one step removed, so I find it less infuriating, and it kills the urge to participate for me. The
Strange Aeons channel is a good example of this, as well as
IzzzYzzz and
SarahZ. Those are usually Tumblr related, but there are others who cover other subcultures.
Whatever you chose, I wish you luck! It's just so easy to fall into phone addiction these days, since everything's designed for it. I think we used to have a "healthy things to do on your phone" thread kicking around here that may also have suggestions if you want to go searching for it.