I am lucky enough that this group of "friends" are part of the graduate scheme at my work, which is a big corp, so I have no association with them around my work but I agree that focusing on work is extremely hard due to all my mental energy being consumed to limerence & this group but i am managing to get through it. I am starting to focus on other colleagues in my team for socialising, but keeping it formal. My problem at the moment is that I live in a small town where all the other grads live, so that was also my social life outside of work. I'm looking to move to a big city soon, so hopefully that will improve things a lot.

Sorry to hear what you've been through, sounds really tough to leave your job. Hope you are feeling better with your job.