Well, given your history, I would question you too.
In fact, I am questioning you right now.

Ok, I'm done.

I do believe you that you have the hots for your wife but I don't blame her for the line of questioning. As women, we end up trying out several different scenarios in our minds to explain why a red blooded male would not want to ML to us. After all, society sends us the message that men are sex hounds from the time we are little girls.

Historically, were you ever the sexually aggressor in the R? If you were, then you can gently remind her of that and build on those times.

Also, I think getting control of the masturbation will only add good things to your marriage. My H and I don't masturbate at all, and while some think this is extreme, I can tell you that it HURLS us towards each other in a way that would not be necessary if we were mbating.
NOPkins once posted that he wished that he and his wife had taken this journey at the age that we are (mid to late 30's) and I didn't write this out but I thought, Hell YES I'm starting now...if 100% of my sexual energies are directed towards my husband, then we are GOING to fix this! If he is my only outlet, then I am going to make our sexual R the best it can be..there is no other way.

Again, I'm certainly not suggesting that this lifestyle is for everyone and, quite frankly, I don't really care what other people will do...I just wanted to say that MB can pose a serious hindrance to an already difficult problem. If you are avoiding your wife, it makes it all that much more easy to continue to do so. If your only outlet is your wife, you are mentally AND physically motivated to make your relationship good.
Maybe someday after you've worn your wife out, you can reinstate it (if you want to) but for now, I think you are wise to cut it out and devote your mental, physical and emotional energies towards her.

Speaking of wearing the old girl out, do you know what her frequency preference is? How do you feel about that number?