Hi OP, your situation sounds so similar to mine. I've been married 20 years, children have their own lives now though still need me, they are pretty much independent. My DH has, I'm sure, had affairs though haven't been able to prove anything, yet I know he loves me and would do pretty much anything for me.
I k ow people will see this as contradictory. I know tolerances are different but for me, my love towards my husband has changed from full on passion to comfortable habit, almost brother and sister. Love is love and I frequently find myself thinking " well if he's not waving his affairs in my face then I don't care ". Again most on here would respond to that with LTB but I don't want to, I love him but just in a comfortable, excepting way.
I had an emotional affair a while back, I needed to feel something different from " comfortable."
It was fun but as it became more intense it made me look at where I was in life. Did I want to start a relationship all over again? What would happen once the honeymoon period wore off?
I just didn't want to go there. My lot wasn't actually that bad. In fact with some tlc towards my marriage, I k ew I could be happy with my marriage again. And that what I did, I ploughed time and energy into my own well being and my part in my marriage.
Months later I can hand on heart say, it was worth it.
Yes, shock horror, men and women have affairs. It's escaping but it's short lived and highly over rated. It doesn't sound as though he wants to go, doesn't sound like you want to go. Just apply time into you and your husband. This feeling will pass once you change your focus.
Hope this makes sense.