Recent marathon swim .... your thoughts, please?

I recently participated in my 3rd Valley Forge Marathon Swim, now renamed the Charles Bender Memorial Marathon Swim. This is an 8 mile swim, but I made the 8 miles only once, last year. This year, I got to 6.5 miles. Yet while I wish I'd been able to finish, and I do at times ask myself if I really needed to stop when I did, I did accomplish something w this swim, which begins w about 2.5 miles of downstream swimming before we turn and swim upstream 4 miles, then back w the current. Of late, the current has been a lot faster than last year, although it mercifully slowed to about 1600 cfs (after highs of close to 3000). What I most dreaded this year was swimming against what we'd had lately, so I was relieved to see the lower number. Still, 4 miles upstream is still a challenge. This year, I was determined to push the pace more so I could reach the downstream stretch at the end sooner. That was pretty much working out all right, and although obviously, I wasn't going to progress at the same rate as with the current, I was making reasonably steady progress. However, there were a couple points as I got closer to the turn that threw me off a bit. There's a set of buoys marking a channel intended to keep us off a shallow, rocky stretch. There, simply swimming a little harder than usual wasn't enough. I needed to sprint. But it was a short enough distance that I made it through and could ease off a little (though still pushing my pace some). The turn-around buoy was preceded by an even faster current. And for some reason I'd forgotten from the previous year that after the channel marking buoys, it was still another quarter mile to the turn. I'd entertained the false hope that it was almost immediately after the channel buoys. I know a quarter mile isn't that much, but psychologically when the kayaker told me it was a quarter mile, I was taken aback. But I settled back in and made the best of it, and eventually the turn buoy came into view. As I got within about 25 yards, though, the current that had been against me but doable turned into what felt like an endless pool current. There was talk of offering me a tow, but I wanted to do it without help if at all possible, as finishing would mean much more that way. Still, it was supremely frustrating. I'd pull even w the buoy after a 50 freestyle effort, start to swim around, and be pushed under the buoy and back 15-20 yards w/out having circled it. On maybe my 4th or so try, I decided to aim for getting past the buoy by a few yards, and finally circled it. But that effort cost me. Even after a breaststroke break and a feed, I was feeling depleted and a little queasy, muscles tight and very sore. And although the water temp wasn't that cold (just under 70f at the start, maybe low 70s later, I was starting to shiver. That was the first time I felt cold... I'd been fine w the temp until then, despite it being a little cooler than on previous days (I train there, so that helps--I'd been acclimating as the temp went down). I asked myself how long I'd be able to keep going feeling that way, and decided to pull out. In hindsight, maybe I could have kept going, but I refuse to regret my choice, just learn from it. Nutrition was good, feeds 20 minutes apart. Pace was, until the turn, better than the previous year. And I like that I persisted and got around that really hard turn. Longest swim in training was 7 miles in a pool. That's something I'likely want to change. State of mind too. I let myself get into too much self doubt: the negative tapes... "I'm bad at currents... I'm not a real marathon swimmer.... what if I'm way slower than last year when I was pretty slow?" Afterward, I had decided, "enough!I'm retiring from marathon swimming!" However, the next day, over breakfast w a friend who swam, I mentioned a 10k swim a few wks away as something that interested me.... then, "shut up, self!" Then, "well, next time. ...." -- you see where this is going? I'm 66, and I hope to swim as long as my body allows. To what extent, if at all, do I need to consider aging in the equation? Is it realistic to keep aiming at swims like this -- and longer? Does a person simply reach a certain limit ability -wise? Frankly, I'm not attracted at all to the "I'm too old for this because I reached a certain no of years" way of thinking, and I need to respond better in my own mind to any comment that begins "at your age" or "when you get older...." etc. People don't always mean any harm, but I'm thinking I'm 66 not 96. Older swimmers, especially women, do share your thoughts on what, if any, accommodations you make re aging. I'm not at the moment looking at anything as exalted as the EC, but maybe double digit miles.... though I admit the EC is one of those fantasies I occasionally indulge. There was a time when I thought a mile was pretty long. I've gone well over that quite a few times, although I'm not speedy. (Training SCY, 2:00-2:05/100 is a hard effort.) Finally, my coach, who was also the race director, told me he thought that was my "best marathon swim," mainly because of getting through those hard currents. I trust him b/c he doesn't praise lightly. Thanks for any perspectives. Sent from my SM-N910V using Tapatalk