I would suggest going to the doctor to get a full well-woman check to make sure something isn't going on hormonally. Also consider any meds that you might be taking. Then I would suggest a sex therapist or addressing it more with your regular therapist. Being repulsed and anxious about sex can definitely cause issues for both you and your relationship. Plus you mentioned the PTSD and that can be a mountain to overcome and can definitely kill your libido.