A few people have responded to this already, however I'll add one more...
more than 16 years of my life with him would say otherwise. He knows that I love him. There's nothing ambiguous about that.
Here's the analogy:
Imagine the babysitter that you've used for the past 5 years, and that has always seemed good with the kids, shows up one day with a gun in her hand and shoots all of your kids, putting them into the hospital with severe wounds that almost killed them. A few days later, she calls you and says, "So, would you like me to come same time next week to watch the kids for you?"
Would you ever let that babysitter anywhere near your kids again? But what about the last 5 years when she didn't decide to shoot the kids for no reason? Doesn't that count?
When WE (WS's) look back at our marriages, we often tend to try and focus on the good things. Which, lets be honest, are the things we didn't lend much credence to when we had our affairs. But our BS's often look back and now only see the precursors that they missed. The act of infidelity poisons everything. For them, those past 16 years are now meaningless
This is important to understand. THEY NO LONGER KNOW YOU OR TRUST ANYTHING YOU SAY. PERIOD.
You say you had happy 16 years. How does he know that? How does he know you didn't have another affair before this one? Or ten? Or a hundred? How does he know you aren't still having one now? Or will have another in the future as soon as things get tough?
The answer is, he doesn't know any of those things, not for sure. And where he once may have simply given you the benefit of the doubt, look where that got him. He trusted you, and in his book, you took advantage of that trust, in the most painful and cruel way possible.
Whether or not you are still technically married, and whether or not he still wears his ring, the marriage and the relationship that you once had is now over. You can always build a new one, a better one even, but the one you had is gone. It just is. There is no past 16 years because he will never know how much of it was a lie, and will now look back and question every "I love you" and wonder if that was manipulation, or how you benefitted from his love. He may feel like a chump for ever trusting you or the relationship.
Please don't misunderstand me. I am in no way trying to critisize you more or make you feel worse about yourself. This is advice on reality from someone who also had to swallow that bitter pill, and didn't handle it so well. So I'm hoping to help you to get there faster and with better understanding than I did.
Just imagine that you are divorced and meeting your husband for the first time, because in a way, you are. He nows sees "the real you" and you may see it as well. So in order to win his heart again, you will need to start over again, and this time, it's all uphill.