People use whatever crutches they need; food, alcohol, drugs etc. They are self-medicating in a way, to relieve the stress or forget about the emotions.
If your health system won't adequately treat your PTSD, perhaps you could get treatment for sexual abuse. At least be examined again to make sure the real problem is being addressed medically and psychologically. You could be suffering from a combination of things that add up to PTSD, or some other diagnosis, but you probably don't need a generic treatment.
Once you get treatment for the right problem, life will get better and you'll feel more like taking charge.
Hope this helps,
"That which does not kill us, surely makes us stonger." - Neitsche