T.C.
Bad days? You have bad days?
Just kidding. I have two with ADHD, so I feel ya. Without knowing specifics, here are a couple of thoughts:
1. Do not buy into "cures." If this thing could be cured, we'd all know by now. It's a complex puzzle, and lots of people out there have pieces of the answer. If a diet works for your kid, then do it. If it doesn't, it does not mean you did anything "wrong." It means the diet was not a cure.
2. Check out http://ldonline.org/. It has parent forums and all kinds of good info. CHADD is a good resource, too.
Lots of people out there are ready to help you out. Inevitably, you will also run across people on a mission to convince you that drugs are evil and bad and that you will be a rotten parent if you use them. Ignore them. They don't have any magic answers, either. In fact, ignore anybody who tried to make you feel like a rotten parent. (If you're like me, that's a job you don't need to outsource--I'm plenty hard on myself.)
3. Mindfulness. My daughter's therapist once took a whole session that was supposed to be about my daughter and concentrated on me, because I was so obviously stressed, and I took away this piece of advice. When your kid's having a meltdown, when a vital piece of paper is missing, when the teacher calls for the fourth time this week...just say to yourself, "I'm going to let this flow right through me." Don't get yourself in constant "fix-it" mode. Much of this is beyond your control; some crises will pass if you do nothing at all. Do the best you can--and after that, cut yourself some slack. Hope this helps.