You know Bella, it sounds like, from your description, that the property you live on is just too much for you (Physically and financially). However, you really don't want to do apartment living, as it's just not the right fit for who you are. Beach towns are wonderful, but everyone else thinks so too, and they usually aren't very affordable.
However, perhaps living within an hour of the coast might work for occasional day trips. Maybe you could find a small cottage in a town within that distance that has a fenced-in back yard for your dog, and still room for a vegetable garden (Maybe not large one, but how many zucchinis can one person eat). If you could find that, it would drastically scale down maintenance, responsibility, and maybe give you more freedom.
All of us hate the thought of getting older, and our choices being narrowed down, but that's just reality. I'm not suggesting you give up what you want, just maybe a compromise or happy medium. It may require some openness to relocate, but if it will get you what you desire, then it's not so bad. Just my thoughts.