Well, it definitely sounds like your not in the most ideal sexual state of your life.
. She shouldn't make you feel bad about masturbating, if you're horny you'll get the urges out one way or another. I'm definitely no therapist, so I definitely don't know everything about relationships, and don't want to give you that impression. All in all, it seems to come down to the fact that you're just not being fulfilled sexually. Sex can get boring in a long term relationship even with oral sex and trying to be spontaneous, let alone the situation you're in. I think the sooner she knows that things need to change sexually between you two the better. For me, if my gf and I don't have sex at least occasionally (once a week or so), the sexual frustration builds up for me and we get irritable with each other. I think if you're wife is willing to hear you out and potentially step out of her comfort zone to make sex more interesting, you'd be on the road to a better sex life. Good luck with everything, I don't envy your position as I think its going to take a bit of work to get things back on track.