If he is approaching 60, that puts you at about 47 and I really don't think that is going to be a major problem for ya'll. It just seems that after about the mid-forties, we all become about the same age. The ages just sort of blend together. I would see the age difference as being of much more significance with someone in their 20's or 30's and a partner in their late 40's, 50's, or 60's. That would be a more difficult bill to fill in terms of everyone having mutual interests, body types, energy levels...all those sorts of things. I'm 55 (almost!) and consider anyone from about 45 - 60 to be in my age range.
Maybe you want to tell us what was unsuccessful about the other experiences. There might be something going on besides the age issue (since it doesn't seem like an issue to me). Lots of good advice to be found here and you might get information to help you. - EBF