Idk I have the same feeling (losing interest) for already like 5 months. But there is no person affecting my interest
Can't really tell you how to help it, but can just share my experience.
Stopped playing LOL for 3 weeks or so-- got even worse. I think the point when I stopped playing was fatal. I am that kind of player, who heavily relies on constant practice, each day I was losing my skill to the point when I became an average or even worse player. I could no longer go ranked, and normals at these times were filled with some shit like heim adc. This made me lose even more interest in game.
Kept playing LOL 2-3 hrs a week and mainly was playing some single games. Not bad feeling, I was still playing, but it wasn't toxic, very bearable, because I can always hit save and exit or load last save if something goes wrong. But in several weeks I realized ,that I still treat LOL like my main game and I need to play it.
Decided to go ranked, because normals were filled with total trash meta. It was a mistake, my skill dropped so bad, that I couldn't nearly close compete with my current rank.
In addition to this Rito kept trashing sups, and now my main sup starting build is fucked. But Nexus Blitz helped me to keep my interest. Right now training mid champions I always was attracted by to start playing mid in ranked. If by the end of the season I won't start doing as well as I originally did with support. I might try other online game.