Find someone else. Yes you can be happy alone, as can everyone. But perhaps now is a time to just move stuff into someone else.. even if its just another little crush, or something better?
Fill up your time as well. Just try and keep busy and see people. Not them. And don't let them rule over things, say if you talk to them a lot.. try and limit it to the amount you can cope with.
There isn't really a proper solution, but it'll get better.