You've got a couple of months.
So, couple of things: Posting on mastodon is posting publicly, as in web-searchably publicly.
Don't use your real name unless you're going to exclusively post stuff you want immediately traceable to you.
Second thing: Big tech is not your friend. The big tech companies can be made to rat you out by law, but most likely they will be falling over themselves to offer you up on a platter.
De-google. Someone on here can help you. Phones are the hardest, email is the easiest. All is doable.
Remove all meta apps.
Threads, bluesky, don't trust those - keep them on a 100% anonymized and locked-down device if you absolutely must.
Start learning to use a non-Microsoft and non-Apple OS if you don't already. You have time to build this ability on the side.
People on here can help with that too.
Those are the basics. There are people who can help you go way beyond these.
ISPs are a second angle to cover.
Don't panic. Breathe. Take the time to boost the lines of defense around your online activity.
Actual experts can explain better and wider how and what.
re: You've got a couple of months.