I had a similar issue when I took some breaks for testing. It's been about 3-4 months since then and I'm now better than I ever was.
The way I battled it was that I just needed to not
THINK about my aim being the issue, just that I wanted to enjoy the game. You might not find enjoyment in playing the game, in the sense of being able to just play maps for fun and not for pp, which is something that a lot of players have (i also do love getting pp).
While I might not have an idea of what goes on in a 30k player's head (64k over here!), having fun was my gateway back into the game. I realized my aim was deteriorating and I can't even remember how it has improved since then because it's such a gradual thing.
Whatever you may enjoy in osu!, whether it be mashing circles to the songs you love, or hitting insane jumps, as long as you aren't feeling pressured into playing better. Never feel obligated to play to your expectations and just make sure you play more (haha funny phrase, but seriously) and are having fun with the game, and you most likely will get your aim back and better in the near future!
Don't forget to take breaks though, as burnout is a bad place to be
