When I first saw the title of your post I composed a letter in my head, saying don't beat your self up, three days is pretty good (there were several times I never got through day one), maybe three days is all your body can take right now, etc. But when I read the whole thing I realized you had a good take on what was going on in your life. Just keep trying, one day at a time, and you will achieve a victory. You have already done more to take responsibility for your health than many people will ever do in their lifetime. That in itself is pretty awesome.