HF,
I think Moveforward has given you some great advice and would council you to consider what she has written very carefully.
I thought I would offer a slightly different slant on this, not to contradict Moveforward but perhaps offer you a slightly different perspective allowing you to use her advice more effectively.
Permit me to begin by answering the questions you asked at the end
This is really a choice you need to make. First, if you want to continue the marriage, I know you will find it necessary to forgive him, but not for the reason you think. You will need to forgive for YOURSELF. Forgiveness is a gift you give yourself. You finally decide that holding the option of punishing him is not worth the emotional energy it takes to keep that reservation in your mind. When YOU can let go of the option of retribution, then forgiveness realizes you from it. There are many books on forgiveness, you should find one or two and read them.
One thing though, don't confuse forgiveness with forgetting. You should never forget and neither should your H. If you forget this happened then you will have also forgotten the lessons you have learned by going through this. That is bad. I would encourage you to talk with your H about this. The WS often wants to move on, but without learning from what happened. I think if he understands that you need to talk about this, learn from this and discuss the why's and wherefore's to make the marriage better, he will be more tolerant of your healing and the learning process. Don't sweep it under the rug, but make it clear you want this marriage to continue but NOT with the mistakes of the past still being made. AND I mean the mistakes you BOTH made in the marriage.
He says he will live the rest of his life for me. He says he will be there to help me through this whatever it takes for as long as it takes. He says I am all he ever wanted.
Notice the part I put in bold? This statement may well be very very true. But, consider the context. You are focusing on the marriage again. You are not pregnant. You are not depressed by your miscarriage as I am sure you were in the time afterwards. There is a message here, perhaps many messages. You two need to talk about this. You see during the period you described you were NOT meeting his needs. You know that and he knows that. Further, you KNOW and so does he it is not an excuse for his decision making at that time. BUT... (there is always one of those isn't there <img src="/ubbt/images/graemlins/wink.gif" alt="" /> ) if you could not have met his needs you should at least have acknowledged that his were not being addressed and your intention of doing so when you could. I am guessing that you never had that discussion with him, and it influenced his poor decisions. Do you see the fine line here?
I am NOT saying this was your fault, it was not. I am saying the marriage could have been stronger if you recognized that you could not meet his needs right then, and expressed this to him. You could argue that he should have KNOWN, you could argue that it didn't make any difference it did NOT justify what he did. You could be right but at the cost of your marriage. We are talking communications here and that is something you two really need to address.
Do I rejoice in this and trust him again? Is all this pain just self pity?
Is the pain self-pity? Probably. Is it justified? Yes in mind mind it is. Is pain from betrayal normal, you bet. Is it deep very deep. It has been compared to losing a loved one, you probably can answer that one better than most.
I think the answer for the trust part is to rely on Ronald Reagan's advice..."Trust but verify". <img src="/ubbt/images/graemlins/laugh.gif" alt="" /> Seriously, you should trust your H, but it should be based on data and actions, hence the verify admonition. It is actually what Harley says is best in a marriage. He claims 'blind trust' is not good for a marriage because it leads to taking the other for granted and we are all capable of cheating if the situation is right. I am not sure about "all" but I do think the temptation is there.
You then asked
How could he love me and hurt me so much? We have always been so great together. Even in the most darkness of hours we have laughed and cried together. We have been together since we were kids and grown together and have so much together.
Given what I have read on this site for the last 7+ years, I would be inclined to agree with this statement as the answer to the above question
He says that during our most difficult days with 4 little little kids he felt unimportant and needed reassurance and she was there and he feels ashamed and embarrassed.
There is more to say, but I would encourage you to read on this site about REcovery, needs, and love busters. I think as you read you will see the patterns and the way to rebuild your marriage. There are no short cuts around this stuff, you must go through it, and it does take time.
God Bless,
JL