Everyone goes through anxious moments in their lives and its important to work out why your having anxiety and repair those issues which will in turn help to address your anxiety at the same time and help you to understand why your having it.
You cannot change the things you have been through, but what you can do is make peace with those things by looking at what you have learned from those moments. You can always write it out which is proven to be healing and express it to help someone else here :
Also try mindfulness techniques which is learning to live in the present. http://www.helpguide.org/harvard/mindfulness.htm
Acknowledge-ding your past is a good thing but you don’t need to relive it as your future is right now, work out whats next for you.
The things you’ve been through is what you call ‘your experience’ (your past), but it is NOT who you are. Learn to separate that and move forward in what you’ve learnt from it and how your going to make a better future knowing what you know now.