There was a woman that I was in love with a little over 20 years ago. She was my idea of physically attractive--definitely not most people's idea of attractive--and was so entirely fundamentally broken that it triggered intense feelings of being protective towards her along with desire. She was smart, sarcastic, liked cats (yeah, that's pretty important), and was also entirely addicted to opiates and cocaine. She was very open about how fucked up she was. I was fucked too; I was not a mentally or emotionally healthy person in the least.
If I had ended up being in a long-term relationship with her, I would almost certainly have ended up dead by now; I either would have gotten equally addicted to opiates, or I would have killed myself at some point. Thankfully, since I couldn't supply her with drugs, she wasn't interested in anything long-term with me.
I look her up every so often on Facebook. She's still alive, and posts the same kind of angsty cringe shit she would have posted if Facebook had existed 20-odd years ago (and, to be brutally honest, the kind of angsty cringe shit I used to post before I quit doing anything except lurking). If I spoke with her again, I'd probably have to deal with the same unresolved feeling again, because there really isn't a resolution to them. It would be dangerous to me to get close, and so I don't.
There have been several women like her in my life; I am not in contact with any of them, and I do not plan on having anything other than--at most--electronic communication with them at any point in the future.
Feelings are not enough to make a functional, coherent relationship. Feelings are necessary, but are not the only thing. You can love someone completely, even recognizing all of their many, deep, and varied flaws, and that doesn't mean that it's going to be good or healthy for you. Or for them. Mistakes happen, and you hurt people. You can apologize and be a better person in the future, but you also can't unwind the past.
I would strongly suggest that you work on your current relationship rather than revisiting something your past. There are some things you've said about your own tendency towards avoidance, and about your relationship with your wife, that lead me to think that perhaps you could use some help with communication and intimacy. That's not a bad thing; relationships can almost always be improved. If you are certain that you want to resume contact with this person, I would, at a bare fucking minimum, set very strong and clear boundaries about what is and is not appropriate to talk about, and I would suggest that you should ensure that your wife be a part of this contact--which is to say, a chaperone--so that the risks of going to an inappropriate place are reduced.