What purpose will it serve? Think about his reaction: he will be hurt, angry, and then who knows what else. And you will have burdened him with YOUR guilt AND the unhappy position of making a choice: to end his M or not. Why would you place all that on him?
Whether or not you think this will ever happen again, with anyone, I beg you to take your indiscretion to your grave. Telling someone that you have betrayed their trust - especially someone you still care about - does nothing but hurt them. And what's the point of that?
If you tell him, you will *create* a problem where currently there isn't one -- at least from his perspective. If there is something wrong/missing in your marriage, you first need to identify it, then decide whether or not you will work on it. Together. If you discuss anything with your H, discuss that!
Please take this in the spirit in which it is meant: you asked for advice, and this is mine. If you tell H, you punish him.
Whatever you decide, know that you can come here to vent, cry, ask for support or just share your happiness. Best of luck to you. I hope you can sort this out and find happiness.
I would imagine that the guilt will bring out some soul-searching anyway, but try to deal with the guilt and set it aside so you can get more productive work done. The first step is to try to figure out your own mind, because once you know what YOU'RE looking for, what you want, you can apply it to your M and see where it needs work. Then you can deal with whether or not your M can ever reach your goal, if it's attainable, and if your H will work with you to get there.
I am trying to work out things similarly with my H now, and I am lucky because he is an open and willing partner in this. He knows I have been unhappy, he knows specifically why, and we are working on plans to change it. It's not just me beating him up over what I think he should be doing, how I think he should be acting, etc. I have come to realize more concretely than ever that I need to allow him the space and freedom to be HIM... not who I think he should be. And that's a huge step for me. A release of control. It's a little scary but also very liberating for both of us, and I think we are beginning to enjoy each other more.
Wow... thanks for letting me get that out there! I do wish you all the best and do come anytime to post, update, etc. It's nice to get to know you.