I'm sorry you're having to sit with these distressing emotions. I don't want to pass judgement but from what you're describing it might not have been a healthy relationship for you so I think now is the best time to invest in yourself. It's one thing in life you will never regret. It sounds like you did your best to try make it work but weren't given the same effort in return. It can be rough because we still want things that aren't always good for us and we can't just turn our emotions off like a tap (life would be easier if we could!). I think it's understandable you are feeling the way you do but don't punish yourself for his behaviour. It might be time to work on building some new habits to take care of yourself. What's some self-care you like to engage in that might lessen the feelings of loneliness? Do you have people that can support you during this difficult time?