A few things come to mind while giving you ideas on how to work through your resentment and fear (which is very normal and expected, btw).
This job is yours alone. Now if he continues to add things to the pile once you've expressed how you feel, then it's time to re-evaluate things. It is not up to him to make you unload the resentment.
Resentment. Man, I carried that load around as long as my back could handle it. Problem is that I walked around a very unhappy person--keeping score and dying to point out to others "Look how you hurt me! It's no wonder I carry this wheelbarrow around." I learned more about resentment as I went deeper in myself. I kept score with others because I was keeping score myself. My self addressed dialogues were filled with "He should/she should/I should", and honestly, with all those expectations, I was setting myself (and others) up for failure and putting more items in that wheelbarrow. The ONLY way I've been able to successfully navigate the resentment bullet is to fess up to myself and tell myself, "Bets, you're doing a lousy job of taking care of your own needs and you're mad at everyone else for not prioritizing you, and the fact is, you're not willing to do that for yourself."
I then sulk for a bit and then begin to work my a$$ off to schedule activities that make me feel better about myself--an hour of prayer/meditation... ignoring my chores and grabbing my girls and the dog and taking a walk... heading over to the massage place and getting an hour rub down... exercising... a manicure/pedicure... calling an old friend just to catch up and hear her voice... writing a letter to my grandmother... you get the idea.
Pretty soon, I find myself completely dumbstruck that I kept expecting someone else to take care of my needs.
Okay, now on to other things. I, too, have an XH who is not very good at opening up. Consider this: he's undoubtedly had lots of experiences of being shut down when he's started to do it. It's going to take some time to learn new techniques and for him to see that you are a safe person. (Didn't we discuss this on one of you previous threads? Maybe go back and have a look-see?)
When I get defensive, it's because I perceive others as attacking me or how I feel. It's because I don't feel safe expressing myself or my needs. I typically feel as though others are looking for me to solve their problems, and I usually feel as though I'm expected to change to make them feel better. (And yes, this was my dynamic for years and I did the same thing to Mr. W.)
Until one day, when I had a lightning bolt hit me. (I actually listened to some CDs on anger.) Instead of getting hot at Mr. W. for behaving some way and thus making me feel lousy, I approached things differently with him.
I spoke in "I" statements. I stopped addressing his behavior and connecting the dots to how I felt. I simply started telling him how I felt (and I still do). "I'm feeling really anxious because of..." or "I'm angry because I'm afraid that we're going to repeat our mistakes..." Mama, it is NOT going to be easy to go deep and start really identifying how you feel. It's not enough that you say you're angry. You're going to have to find out the exact source of your anger so that you can express it authentically--not from the POV that it's his behavior that is causing you to feel that way, but from complete ownership of your own feelings.
"Honey, I'm anxious because I'm afraid. I was so hurt from this experience and I don't want it to happen again. I'm trying to figure out how to work through this fear and am wondering if you can help me?" He might ask how. You might be able to ask him to do a few things that you feel are important, and start small... "I'd like to hear how you feel more often..." or "Maybe we could schedule lunch together a couple times a week so I can work on building that trust and connection with you." or "It would mean a lot to me if we could schedule a date night weekly." Whatever steps you can take to start building bridges instead of blowing them up with your fears and anxieties.
Learn to communicate authentically without projecting. If I could hold a class for everyone I know who struggles with anger, the recurring material would be that it's never about what others are doing or not doing--it's always about how I feel. If their behavior is a deal breaker for you, it's up to you to state boundaries and enforce them. Boundaries for you might mean that you let him know that you cannot allow another woman into your marriage, and if he feels the need to have another woman come join you in the family, you will not be able to stay married to him. Nowhere did I say you issue ultimatums... you simply state what it is that you cannot accept.
But before you go for the jugular, I'd suggest you first master expressing your feelings and needs in terms of you and not at all about him... build blocks to make it safe for the 2 of you to speak openly and honestly without projection. Then build up to the big stuff.
If it makes you feel better, this is constantly on my agenda when communicating with my XH. It's not for the purpose of reconciling or anything close. I just want to learn how to communicate with everyone I know in this fashion--and what better starting point than my XH? He's hurt me the most, but he's the father to our 2 girls, and I am going to have to work with him for the rest of my natural life. I look at this as a teaching opportunity as well. By communicating this way, I'm teaching him (and our D12) how I want to be treated. And guess what? They have learned well. While he's not dying to share his feelings with me, when he's really agitated and takes it out on me, I always get an apology with an explanation of why he's feeling unhappy. He's honest that it's not about me. But if it is about something I've done, he's pretty careful just to tell me that he feels lousy. He leaves it up to me to explain myself or to see that I owe him an apology. And we work from there.
Moving on is a process, Mama. You're not going to wake up one day, ask him for an explanation that satisfies you and then dismiss it entirely and live happily ever after. Moving on requires that you change too. It may require that you do forget his part in this for awhile. Make it safe for him to open up to you. In the meantime, don't you have some bridges to build?
Hugs,
Betsey
"There are only 2 ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle."