If you don't know what to do, try to get involved with helping others in some way. It can be rewarding and give you a broader perspective on life.
Just want to pile on here and say that this is absolutely crucial, both for your chances of eventually finding someone and if not that, for your own sanity.
1. if you go into activities with the ulterior motive of meeting someone, you're not going to be satisfied by the activity itself which will cause resentment.
2. people can sense when your heart isn't really into what you're doing, and this will defeat your purpose entirely causing #1
You really have to accept that you may never find someone to properly get into this mindset though, and that's really hard. But it's a choice and I'm convinced that it's the correct one.
I think this is only because the bulk of the advice in this area is to tell men to become more attractive (cf. "looksmaxxing"), change hobbies, attitudes, etc. That, or resenting women. Most would rather live on hope than fundamentally change their outlook.
I can confirm that this is how I am generally happy in life as a single. Underrated advice.