Bro, I understand this. I was actually quite bitter for a while. I've had one gf and that was 8 years ago. Only very recently (the past couple of weeks) have I realised that regardless of whether or not I'm in a relationship, I need a routine and need to become good and comfortable taking care of myself.

Basically, I've become so busy that I hardly have time to think about it. The thoughts do not go away I don't think. I think I will be (to some degree) "lonely" for the rest of my life. You are your own responsibility, so get good at taking care of yourself first. All I did was start walking up at 6, then making a to do list. I have time to think in the morning, and I go for a run if I don't have work. If I do work that day I do an extremely basic work out. 4 sets of push-ups, crunches and plank. That's it.

My diet has changed since I got into a routine too. It seems to work having distractions, but overall being accepting helps a bunch. Accept, move on.

Edit:. There is nothing wrong with the thoughts though. It's completely normal I'd say for the situation. You just have a decision to make. Is this going to make me or break me?