Losing your job & your GF at the same time is really hard, but you need to concentrate on the most important thing right now which is getting a new job. At least you are free to get a job wherever you want and not have to consider locating near her or anyone else. So try to put relationships on the back burner for now. And don't keep trying to convince her not to break up--obviously she is done, for whatever reasons. Keep in mind that it's pretty hard for an unemployed guy to attract women so once you get a job then you will feel better about yourself and then will be able to go out & look for another woman. And just because this one relationship didn't work doesn't mean that you can't trust other women--she is only one woman, she is not representative of what every other woman would be like. If you feel that you are still depressed, try to get counseling. I know that's hard with no insurance, but maybe you can find free counseling somewhere. (And by the way, look at enrolling in the new health care plans--if you are unemployed, shouldn't you be able to get free health insurance?)
You were "together" for 4 years, but a good deal of that time you were apart! There seemed to be a lot of apart time, and that's no way to build a relationship. Now she wants to end it. Chances are she's found someone that's in the same location that she is. Most women aren't going to wait around for 4 years to see if something will work out. I don't think this is a "trust" issue at all....it was just time for it to be over.
It's too bad you got hit with a job loss at the same time, but now you're free to go anywhere in the world if you can find a job to your liking. As musiclover suggested, look into the new health care laws about getting coverage. Most "contract" work pays well, so you'll just have to make sure you put money aside for insurance. And, just as an FYI, if you should need emergency health care, most hospitals will "negotiate" the charges........often to zero.
Concentrate on finding a job........and keeping yourself busy. Give yourself several months to get your head together, and then start dating again.......there are lots of great women out there looking for a good man.