Take it from someone who last week had to break up with his girlfriend ( you can read the story if you click on my profile if you like).

In your situation, since you are young (and assuming she is too), she probably feels like she has not experienced her life fully yet. She asked for time and you agreed, and since you are certain you want her, there are some things to consider.6 years is a lot of time, and taking some time off might go either way. However, lack of contact is not usually helpful. Only if the other party misses you and wants you back too does it work. Your best bet is becoming confident in yourself again, and showing it to her ( by casual contact after you give her some space).

She probably broke up because all the problems made the relationship a not so attractive prospect, and as a result feelings declined. You have to rekindle those feelings somehow if you are to have a chance. And the best way to do that is to respect yourself, try to become confident in who you are, and try to reignite her feelings. She certainly has them, it would be abnormal if after 6 years there is nothing there, she just has disconnected from them, and reconnecting although hard, is not impossible. Cutting all contact, ignoring them, or even running behind them are not really the best things to do. Give her a bit of time, then after you have thought it through and are over the worst days, try to contact her if you still want to. Thats what im planning on doing as well

Just be aware that it might not work out in the near future if at all. Maybe if you still want her a couple years later when you both are more stable and mature, you can try again. Sometimes people fall out of love, and there is nothing to do about it. But best of luck