Are you or have you ever been in therapy? If you're not in therapy, I believe it's time to go, before this goes any deeper. This could really effect your marriage in a very very bad way.

It's great that you recognized it, but before this gets out of hand, you really should seek help. Please have your doctor refer you to a good therapist. Getting started in therapy is crucial right now.
I see that you live "across the pond" so I don't know how your system works as far as getting help, or if you have insurance, etc. But i PRAY you won't have to wait forever before you can get help. You do need to get this taken care of before it goes too deep.
If you can, talk to your doctor about getting this appointment as soon as you can. I wish you the very best, my friend. And would you please let us know how things turn out? I'd really appreciate it, because we DO care about you!!
God bless and please take care of yourself. Hugs, Lee