Hi Larissa,
You don't offer a lot of context to your situation, but I did read a couple of pages of your prior posts. You are on HRT now, yes? Do you take an anti-androgen besides finasteride?
I ask only because I have also had increased genital dysphoria since going full-time as a female, so I can relate to how you feel. However, I have zero sex drive, so masturbation or other sexual activity is not part of my life right now. Do you think your dysphoria would be less if you didn't have sexual thoughts, or is it more gender-related, as mine is?
You can't, of course, snap your fingers and change your genitals, so the best thing you can do for yourself is have a rational plan for transition. Sometimes just knowing you have plan and you are working towards a goal can help quiet the sense of frustration you feel. You have a therapist, so that is good. If you have an endocrinologist, talk to him or her about your dysphoria and see if there is anytime that can be done about having HRT regimen adjusted to decrease your libido. It might help.
For most of us, being transgender sucks. There is no way to sugar-coat it. It is a very difficult path, and transition is both the solution and the problem, a cure and a curse. Hang in there, sweetie. It can and does get better.
With kindness,
Terri