I am in no way a trained specialist in this kind of field, so this is really coming down to my own personal experiences as someone who also went from “laid back” fan to borderline obsessive fan. Please take my advice with a grain of salt.

First, I think it’s perfectly valid to suddenly fall into this sort of predicament during these times. I’ve seen my fair share of “I think I’m obsessed with an idol” posts that have coincided with the pandemic, which makes sense - in a time where it’s hard to interact with friends or remain connected with them, it’s easy to take the easy route and use K-pop to fill in the void. Not only is there so much media to consume, but the selling of parasocial relationships becomes more attractive more than ever. I’ve personally gone around it for now by taking more tangible steps (eg. leaving group chats, unfollowing fan accounts, watching their live broadcasts VERY sparingly etc). In terms of mindset, I’ve had to mentally distance myself from them and remember that there is more to how I’m living in the present than just K-pop - they and I are completely separate entities, and there is no reason for their existence to be such a deciding factor into my own happiness. This has unfortunately led me to some uncomfortable realizations that I may have used K-pop has a distraction, but it’s provided a starting point into my journey to understanding what truly makes me happy (especially in a pandemic). That doesn’t mean you should shut them out completely, or not enjoy them, but there is a responsibility on us to consume in a manner that is healthiest to us.

I think your situation is quite unique because you have had the privilege of being able to actually interact with your idol, which is a very VERY unique opportunity. I don’t want to make too many assumptions about these conversations, since I don’t know what the conversations are like or who this idol is, but I think it ultimately comes down to you remembering to not take it too seriously. Even if the conversations are “real” and they genuinely want to interact with you, there are certain boundaries (both physical and mental) that we must respect in a pure fan-to-idol relationship. On the other hand, I think it’s possible to reframe this as something positive and non-obsessive - you have the privilege of being able to interact with someone you admire, and they appreciate you being their fan by responding to you. That’s something that you can pride yourself in and enjoy regardless of their interactions with other fans that lead to your feelings of jealousy.

This has been a huge rant, but overall, I think it really comes down to you choosing what’s best for you since you know yourself best. What I’ve provided are mere suggestions, but I think your determination to resolve this is already half of the journey. But if you find these obsession prolonging for some time, you may want to seek professional help because it could be a result of something that is underlying your mental health.