HI Cas Pan, sorry I didn't receive a notice that this post was for me.
I feel for you with not having someone to talk to, I'm the same. I have found an online support group where I have met a couple of guys in a similar situation and email them. The one I'm a member of is for gay men who are married to women, but if you search for MOMs or "Mixed Orientation Marriages" you will find others for women in your situation.
You should see a therapist, they really help. I have found the ones that your GP refer you to aren't very good. It's best to do some research and get one that specialises or has some experience with sexuality. It's more exy but I think worth it.
I like being married and keeping the family unit, but I don't know if my wife can continue to deal with my moods and depression, which stems from me suppressing my sexuality. She doesn't want an open marriage, Im not sure if it would be a good solution either, so we are trying to work it out. Our sex life is quite good surprisingly because I'm gay, I don't even think I'm bi, though I do enjoy having sex with my wife but I still want sex with a man. Our couples councillor says he's married and attracted to other women, but he's committed to his wife and doesn't put himself in situations where he may be tempted. But I think its different when one partner has SSA. My individual therapist says that our ego tries to control us, tells us we're straight and should get married etc etc but once we're exposed to the truth, our should recognises the truth and there is no denying it. I guess that is why we suffer.
I hope this helps.