I too met my husband at age 19, and he was 20, back in 1979.....we're still married by the way!
I understand the mixed feelings...I too have a husband who treats me like a queen, but I think since we met when I was barely out of HS, amd he was my 'one and only', I sometimes feel like I missed the whole scene of meeting MEN. Sorry guys....guys bodies don't even mature fully until they are about 21....
Would I cheat on him? Never.....
My friends are jealous of the wonderful husband I have and I know I'll never find one better than him.
That said...I still can relate to the OP's feelings.