She sounds like she has a LOT of issues around sex. I get how frustrating that can be, but having read all of your replies, tbh you don't sound hugely empathetic. To be frank, you sound like you can hardly wait to bail on your marriage.

I think a key thing for us to know is what SHE thinks about all of this. Is she willing to try to get over her fears? Does she want to have a normal sex life with you? I assume the answer is yes, since you've just started seeing a sex therapist. Personally, since she recognizes there's a problem and is willing to try to get over it, I think you should be willing to stick around long enough to try to help her, if you love her.

Obviously, if the therapy doesn't help (I'd give it at least a year), you'd need to look at things again. But if you're determined to leave now, please do it with the minimum hurt to her. She's already dealing with a debilitating condition; she doesn't need to be told that you're leaving because you can't wait for however long it takes for the therapy to work.