If you just want to get some exercise and have some fun get a snorkel. We have a guy at the ripe age of 91 who swims every day of the week. Guy is my hero he is a disabled WWII vet and just gets in to be there he is awesome.
I do think a snorkel could be a great way to bypass some of what might be bothering you. Maybe after a while you can try it again? Snorkels have a lot of great applications. Learn to get comfy.
Good luck hope you don't quit.