Jeepr,
I'm going to take a different tact here, mainly because there are a lot of details missing. The thread is a lot about you and your feelings / frustration and not really what the true source of your feelings are.
I don't know the circumstances of why you pushed this girl away and whether with a good heart felt apology and conversation you could fix it but it sounds like the break up was the source of your frustration and depression. If you love her and can openly, honestly and sincerely address and apologise for what happened then perhaps there is a chance for reconciliation?
I don't know if this is what you want or what will help but I do know that people who are truly remorseful and beg for forgiveness with sincerity and integrity stand a much better chance than others.
It will take courage and conviction and must be authentic but if you think this girl is the source of your troubles then I challenge you to give it a try. Don't make any excuses for your behaviour, accept responsibility, don't put any of it on her (even if its gets heated), just accept and take ownership for your role in what happened.
It may work, it may not but I think you will at least get some closer, perhaps some good advise you can take away and apply in the future, or if you are lucky...a second chance!!
I'm not an overly spiritual person myself but there is some great advice and support in the previous posts. Maybe god is helping you.....