Wanttobehealthy, IMHO, when one door closes, it means there's another door opening that is going to be much better than the one that closed. I've lived long enough to see that in action. Yes, you have learned some lessons (painful ones, no less) and yes, regret is a part of life, but keep your eyes open for the door...its there or coming soon...don't put the blinders back on or you'll miss it.
You have a whole life ahead of you - time to turn this over to your HP and wait and watch for the new door to open. Or maybe it already has and its time to investigate it. Either way, you are going to be ok. Things will happen as they are meant to happen. There is a reason for everything.
Stay strong!