Although I agree that Coastie is laying on the black crepe paper a bit too thick, he and law2doc made some EXCELLENT points. And this is from someone who has been there, done that (med school and residency).
The OP's dream of plastic surgery is very likely unrealistic, simply because very, very few med students (of any age) make it into that field. It is somewhat akin to becoming a pro athlete. And you can't just will yourself to be able to do it. If that were so, there would be many more dermatologists, orthopedists and plastic surgeons, and fewer family docs and psychiatrists. Even ER, which the OP mentioned, isn't that easy of a field to get into. If the OP truly really has a hankering to do plastic surgery and not much else, then I agree that getting a PA degree or RN could be better and faster. I know he has shot that idea down already, but it's actually a pretty good one.
I don't disbelieve that the OP is bright...you don't usually get paid 100k to do anything unless you are good at it. However, he needs to realize that sometimes the idea of doing something is more attractive than ACTUALLY doing it. There's lots more people who think they want to be docs than who actually would LIKE being a doc. There's a ****load of paperwork involved, sometimes abusive and angry family members and patients, and more work and studying than you would ever believe.
I have to disagree with the person above who said that stamina/work ability doesn't decline somewhat with age. I'm 34 now and I would say that I don't have quite as good an energy level as when I was 25. It's not really that bad right now, but I honestly couldn't imaging going through certain residencies, like surgery, at 45 or so. It's honestly very very physically demanding to take 30 hour calls every 3rd or 4th day. It just is. You don't have time to eat enough, a lot of the time you don't have time to urinate when you need to, sometimes you get zero sleep. And then you could back and do it all again...and again...and again. There are specialties that are better, but if I had 2 kids, I'd do some serious thinking before committing to an MD or DO degree. It's not that it CAN'T be done, as obviously people have done it. However, whether YOU SHOULD DO IT or YOU CAN DO IT or YOU WOULD LIKE IT has yet to be determined.
In short, I think the OP is putting the cart way in front of the horse. First, find yourself a good university, enroll in a few courses, see what happens after a semester or two. Consider cutting back your work hours a bit so that you have time to study. See if you like biology and chemistry enough that medicine still attracts you. Later you can get your feet wet with some volunteer work in a hospital or clinic. You're getting way ahead of yourself.