Have you ever really examined closely why it is okay with you for her to be with other women, but not with other men? She could just as easily fall in love and leave you for a woman as she could with a man, if that is what you fear. I think unraveling your prejudice and sense of competition about that would be useful.
It also seems to me that perhaps a good deal of your self-worth is wrapped up in your career and work situation, which is common for most men and another good area to examine. You may do well to find some sort of "back to work" career counseling program to give you something much more constructive to focus on, such as looking at your skills, acknowledging your talents, and developing self-esteem and confidence.
Lastly, I think the two of you need to make time for each other. Go out and socialize together, have fun, give yourselves some good quality times where you are not discussing the relationship and simply enjoying each other's company.