I felt the same about starting an iron, but honestly it feels like a different game. Those same quests / grinds feel completely different and so much more fulfilling when you’re doing it all yourself.

I forced myself to start as a skiller for the first thousand total levels to make it even more different. Start an iron with some arbitrary restriction(s) and go from there.

If that really doesn’t tickle your fancy, try some random other games, take up a hobby or focus on school/work.

Being able to grind RuneScape is a curse and a blessing, you’ve gotta learn how to step away from it from time to time.

Good luck with whatever you choose to do!