Is it possible to be rated 100 elo?


Not too long ago, I took a 7 month break from chess due to similar burnout. I didn't go for as long as you did, but I do understand the plummet in elo following. That's to be expected though, as chess is all pattern recognition, and being gone for that long does take a toll on that. My elo bounced back even further than it was before, and so will yours if you wish for it to.
For now, don't sweat it, you won't drop to 100 elo. It's a game, so the most important thing is you're having fun playing.