I too suffer from PTSD, and I know how terrible it is to experience the symptoms. I also have recovered a huge amount since I was diagnosed, and although i'm not fully recovered, I can deal with it so much better.
Getting help from someone professional is probably the best thing you could do, speak to a doctor about it, keep seeing your shrink, tell yourself that you're going to fight this and keep trying and trying even when it gets so unbearable that you don't think you can cope.
It's great that your girlfriend used to help, but you can't always be totally dependant on other people for support. Of course they can be there for you, but to really get over this you need proper support. There is all kinds of things you can do, you just have to find the right way that helps for you, depending on what Traumatic experience you had.
Keep people close to you, it's not something easily done by yourself. Reach out and get that help, it really is worth it.
You can PM
me anytime if you want to talk.