I think you're getting to the root of the issue. I think it's low self-esteem - I'm dealing with the same issue. I recently turned down a higher paying job (actyally, I quit on the first day - while I still had my old job) that would be closer to family. I was on a 2 month paternity leave, and was already burned out at my current work. I had a 8 wk old boy and was offered a higher paying job in a lower-cost city (38% lower!!!) but on my first day, I was depressed and felt like it was a demotion - the work was kindof a step back from where I already was. I was so fragile, with my lack of sleep since the baby arrived, that I felt nausia and was feeling like I would "snap" or go crazy if I was there for 3 months. The city didn't have many other opportunities - so in my fear, I stayed with my current job and city. Needless to say, my wife and family were a little disappointed - they had gotten their hopes up. I felt like I failed as a husband and father. Because I broke under pressure at a critical decision point.
So now I'm still at the same blah job, in an expensive city and we bought a condo to stay here for a while which puts more financial pressure on me.
For 6 months now, I've been dwelling on how easy it would have been financially and help-wise (with family support for watching the baby, etc.)... but I made the choice to stay in a more difficult area because of the "possibilities" of what it could mean in my career.
I had a little depression and career burnout before the decision, but that first day of work and the decision I made put me over the edge. I returned to my home to find out that I had ALREADY "snapped"! I couldn't concentrate on anything. My mind was moving a thousand words a second, I couldn't sleep, I lost my appetite. I felt to empty inside. Life felt hopeless. I often went to bed hoping I'd wake up the day before my decision.
But now, like you, I'm trying to discover more about my personality. I've realized that I must accept the decision I made, and accept that it was the right choice for us in the longrun. If I had taken the other job, I may have resented my wife for her having us move there. Now, I'm learning about how I've had control issues, low self-esteem, depression, and a lack of understanding MY authentic self. So even though this may not be the best situation (I was also a perfectionist), I am still in a GOOD situation, and If I put my efforts and passion towards discovering who I am, and what is important to me (and my family) - I will succeed. Even if it isn't financially. I have to treat it as a blessing in diquise.
I've been using coping.org daily to keep me grounded. I still have some subtle panic attacks and breakdowns, but I'm trying to counter it with a positive mindset. It sounds like you can achieve your business objectives too. (as long as your mind is in the right place). I often feel the slightest sign of hope gets me charged up, optimistic, and idealistic - but then the slightest sign of bad news sends me into a deeper depression. It's such a crazy roller coaster of emotions.
Don't worry about your girlfriend's ex - money isn't everything. And if she didn't already WANT to be with you, she wouldn't be. I'm sure she's frustrated, as you recognize. So try and vent your feelings here or in a journal instead to her - that way she won't get so sick of hearing about it, and you'll have an outlet.
Sorry for the long email. But I see that you and I are in a similar situation, so I figured you should see how your feelings are valid and there are people out here dealing with the same stresses. Stay focused.