I can appreciate how hard this must be for you, and I think it's admirable that you are so dedicated to your wife. That is a wonderful quality. You are also human, and naturally you want to be intimate with your wife. I think all of us can understand that, and how hard it is to be denied that.
I also think it's very positive that you realize that seeking company outside of your marriage was not a healthy thing to be doing, no matter the circumstances of your marriage. It's ok to feel badly about it, but it's also ok to forgive yourself for it. If you are repentant, than there is no need to continue to beat yourself up about it. We just commit to a healthier future, right? From what you have written, it sounds like you have already done so.

I also hear you about wanting to abstain from porn. There is nothing wrong with that. I think it is very noble to be so dedicated to your wife. You can be proud of that. Please try not to be so hard on yourself for the times when you feel you haven't lived up to that, however. Again, if you are repentant - and you sound like you are, then try to forgive yourself. You are human and made a human mistake in a very difficult time. I think anyone can understand.
Can you tell us some more about how you feel like you are having to be someone else around your wife? Is it that you feel like you have to be her rescuer? You are unable to show your own vulnerabilities? I think that might be something to explore.