He might love me, but he actually doesn't know a lot of things he should have asked about. Stuff that partners should want to know. I am aware that women are more curious than me but he barely knows my love history for example. He never asked. And I think that's not right either....
He clearly isn't living up to your expectations as a life partner - whether or not they are reasonable expectations is immaterial, because either they are, and therefore you are justifiably unhappy, or they are not, and he would be better off out of a marriage where he cannot live up to your standards.
I think you need to prepare yourself for a difficult few months - it sounds as if you have made no attempt to communicate your unhappiness, or expectations, to him, until now when it's too late, so it's likely that he, and your friends and family, will be shocked and stunned at the apparently casual way you are ending the marriage.
People do grow as marriages lengthen - couples who have been married for 30,40 or 50+ years are not the same people as when they met - they have grown and evolved together. Successful Marriages take work, they are not something that just happen naturally. Without that, couples can discover that they have grown apart without even realising how far away from each other they have become.
It's probably too late now, but there is a great deal of effective relationship advice online - love maps, love banks, four horsemen - they each have their supporters and detractors, but they all have things in common; communication and commitment.