The number 1 thing that keeps me interested in games, is having people to play with. When I created my group ironman, I never had so much fun. Even tho we're only 2 that's still active, having somebody to play with is key for me.
If I was you, I would find a friend to start playing with, or if you have nobody that's interested in osrs. Join a clan and get to know other people! Or you can dm me I'll gladly add you
Do you know if you're starting an ironman or non-ironman? And what did you try to play before, when you lost interest?