One thing to think about: When you say stuff like "I've destroyed my body," I'm hearing a bit of "I've already messed it up, so it doesn't matter what I do now (and I might as well not do anything)." Nothing could be further from the truth. Taking better care of yourself ALWAYS makes a difference. The sooner you do it, the more pleasant your life will be after, and the easier it will be in a lot of ways. But there's absolutely no point where getting your BG under control won't drastically improve your life and outcomes anymore. Do something today, and if you mess up tomorrow, get back to it and make an effort again the next day.

Defeatism is the one thing that will mess you up beyond recognition. If you think your alternatives are "be perfect every day of my life in every way" and "suffer a stroke tomorrow and fall over dead," you're just going to wind up not doing anything. Don't let perfect be the enemy of good. Do something today, and you just might be able to do a bit more tomorrow. Do whatever you can.