doggiedo,
Imo, you ought to just let go of your ex-bf .
You weren't happy with him ~ he was like nails on a chalkboard to you! He turned you off sexually. Those are pretty big signals there.
Cancel your facebook account and get out to meet different people. When looking on FB, and old desires are brought up, that doesn't mean that you truly DO love your ex. Imo, it simply means that you're lonely ~ and you know that at least HE wanted you. Part of you then begins to fantasize that maybe there really
is something special between you...and off you go again. Get off that train track, running around in circles.
Whether you're at work, home, or with your bf/ex-bf, you're unhappy. That piece leading to happiness is something that lies
within you. Rather than spending time trying to figure out what to do at work or with your ex, think about what you can do for yourself to make yourself feel better. What do you really need? Are you angry with yourself? Feeling bad about thing/s that happened years ago? What are the issues following you? ~ Start with that.
There are also lists of daily activities that you can refer to any time. Ideas that others have had on healthy little activities that bring a smile or a sense of calmness. I can't seem to find the darn link to the list, to bring up for you though.

Sorry! Hopefully, I'll find it to add soon.
I really do wish you the best. I hope that my words don't come across in a negative way, I don't mean it that way. But I do think that you need to get off the path that you're currently stuck on. For yourself (and if you
really want to kick yourself about your ex bf, then fine, you can kick yourself for coming & going with him) ~
you need to focus on YOU!