Hi @Theblueowl and welcome to the forums

This is a really hard place to be in, it's never easy walking away from a relationship, even a casual one. I know I've stayed in some which were long past their expiration date because I didn't want to lose the company and comfort of the other person. When I look back at these times I wish that I'd ended it much sooner as it would have saved me more pain in the long run, a bit like ripping off the bandaid: it's scary to do and hurts in the moment, but it's better than the prolonged pain of slooooowly prying it off.

Considering the loneliness that's keeping you in this relationship, I wonder if you have any friends or family you could reach out and perhaps make extra plans with over this time? Or perhaps you could look into any local groups that relate to your interests or hobbies, like a book club, running club, game meet ups...

It might not be the same sort of connection but maybe it will help the transition.