The only 2 forms of exercise I actively enjoy are swimming and walking. I find it difficult to advise, but would just like to share in the hope that it may help. I was brought up to take an interest in the natural world and like M0nica, always find something to notice and delight in when I am out walking.
I prefer not to walk in a group, but there are a number of walking groups in my area - from short 'health walks' to longer rambles. I know some folk prefer walking in a group, and the discipline of turning out at a certain time.
I now have to use 'Norwegian poles' to go more than a mile or so, and wonder if that might suit you.
I'd suggest looking around for some exercise that does suit you if walking doesn't.
Have you ever been to see a Spiritualist
Sometimes I walk along and hop on a bus for a stop or two, change my route back, endless possibilities.