How have others gotten past the disappointment and even resentment of not getting anything in return?

Well, you just make a good life for YOU. Now you don't have to do this forever, just a set period of time. I think they say around 3 months. So set a date in your head, and make a good effort until that date.

I can do that and have my time frame in mind. I do plan to investigate further in the new year. What I find out there may change my plan or it could make it easier to continue without disappointment or resentment. If there is no affair, then I think it will be easier.

Sorry you find yourself here but welcome. My story is similar to yours in that my W had an EA with a coworker. I found out by seeing an email when she left her email up on our computer at home.

"Stop asking questions. Be cheerful, warm and loving."
"Well, you just make a good life for YOU."
Believer has given you great advice. That advice is what got me through it. Your H is still with you which gives you a great opportunity for a plan A. When you are at the bottom it looks like there is no way you can recover it. It's been 5 months since my D day and I can say my M is better today than it ever was.

Have you told your H what you have found yet? If not I would try to find out a little more before telling him and instead just start plan A. That is what I did and it helped me find out a lot more before my W and OM could make things a secret. Does your husband use Outlook for emails? If so there might be a way to retrieve emails he deleted. I was able to recover a few emails OM had sent my W. I hope that there is nothing more than what you have seen but it's best to find out as much as you can as quick as you can before you expose. Regardless if it is just a friendship, it shouldn't be kept a secret from you. Good luck to you.

So now my mind is moving forward to prepare for what I might find out. I've resisted doing the work to find out exactly what's going on, but I'm resolved to find out what I can.

I'm concerned about how things may go if I find information that I need to confront him with. I've read that most WSs are angry about the snooping. This is something I'm quite concerned about because he holds grudges and carries around resentment. I'm very worried that this trait in him will be a big roadblock to recovery simply because he won't be able to forgive me for snooping into his personal space.

I understand that the alternative to confronting the issue if necessary is just living with it and not standing up for my M and myself which is a pretty lousy option.

I haven't done a very thorough search on how to confront with facts, but wonder if someone can point me in that direction so I can start to see what it might look like if I have to do it.

Since you're already doing Plan A, why not just pop the letter addressed to OP into another envelope and forward it to her with a short note, something like: "Here, this arrived for you at our house. Thought I'd forward it along." and simply sign it "Mrs. ________ "(H's surname).

That should kill 2 birds with one stone: It will let BOTH of them know that you are aware of the A and of the OP's presence, and will allow you to seamlessly follow through with Plan A in a very convincing way.

I like the simplicity of that approach but from what I've read here, and I am by no means well-versed, that will leave them the opportunity to make up excuses and/or hide the relationship deeper making it difficult to gather more proof.

You say you have resisted doing the work to find out exactly what is going on.

Please, do that work. You need to know what you are dealing with here.

Don't be concerned about how things may go when you confront him. If you have a way to do the work to find out what is going on--do it now.

If you don't feel comfortable confronting him with the facts that you have, get the facts then folks here can help you with suggestions with how to confront him.

My FWW hates snooping. Hate is a very generous term for how she feels about it. She hated the fact that I went through her emails, phone records, anything else I could and told me so. My reply was, "I hate the fact that I've had to look through emails, phone records and anything else to find out what shouldn't have been happening and what shouldn't have been kept a secret from me in the first place". She never said another word about it and realized that the first 5 years of our M that I gave her 100% trust she did not deserve. And I did trust her 100%. If it wasn't for the fact that she left her email up on the screen I would still to this day probably not know anything about it.

Take it in steps. Don't worry or even think about confronting yet. Take the next few days or weeks to find out all you can. Once you find out everything you can, then you can worry about the next step. Everyone on here has been through it before and will guide you. They guided me. I would have been lost without the people on these message boards. Don't be afraid of what you might find. What has (or hasn't) happened won't change because you come across it. But it will make it easier to recover your M if you know what you are up against.