Years ago I was at lake swiming with friends. I am a metocher swimmer... but the day was beutiful, sunny and warm so I kept swimming further out in the lake. I just kept swimming and swimming further out until I reached the middle of the lake. I wanted to reach the middle. I did, but then I grew tired... then I began to wonder how I would ever make it back to shore!
I was about to panic... but I decided not to die... so I dog-paddled awhile ...then I swam on my back, which I can do slowly all day long. I eventually made it back to the shore. When I got back I felt accomplishment. I may not be the greatest of swimmers... but I can stay afloat and make it back to shore from the middle of the lake. Yeah!
A bit scary situation. You did exactly as you should, well done.