A: I suggest that you proceed on two fronts: one being psychological and the other being Tantric. The reactions you describe are very similar to those of women who have survived yet completely forgotten trauma from early childhood or from past lives. That's right, I said "past lives," in lieu of any other possible explanations.! So with qualified, experienced, professional help you could discover the root causes of your reactions, and either verify or rule out suppressed trauma. I also suggest you access those professional resources (a therapist or a specialized support group) before you begin Tantric practices, just in case some deep emotions and "body memories" get triggered. If there is no qualified professional in your area, consider traveling or working over the phone.
At times Tantric practices can be very healing. Sacred Spot massage, if practiced by someone who is capable, well trained, and loving, in a safe, guided setting, can be very powerful and healing for women who close down before orgasming. Check out several of the videos on this topic. Make sure that you explore this ritual in the presence and guidance of an experienced Tantra teacher - this is much more than a technique. Also if possible get training in "Sexual Energetics," developed by Lori Starr and myself. The premise here is that internal body tension and restricted breathing dramatically limit the ability to achieve orgasm.