I can tell you I thought the same thing.... perfectionism, anxiety, you name it. My DD has them both and yes, I think they all contribute. Regardless what the issue is, getting the emotions under control is what you need to work on.
As for my previous suggestion, My DD never ate a lot of sugar either, but I never realized how much she was getting over time through out the day, until I really started paying attention to labels. Anyhow, being consistent with "coping tequniques" is vital to success. I can't say DD's outbursts are totally gone, but now.... they only last seconds instead of the length they used to. She quickly realizes what she is doing and immediately catches herself and stops. It almost becomes habit as that outburst because their way of coping. My dd was very "intense"... emotionally, physically (meaning labels on clothing bothered her as a younger child... still do sometimes, but not like it used to. She would never wear certain things because of how they felt on her skin. Over stimulation seemed to cause anxiety, lack of sleep brought out the behaviors.... all of these things were triggers. Over time, you learn to know what can and can't bring out a melt-down and try to curb it before it happens (not by distracting so that it won't happen, but to teach the coping technique to deal with it when it does.)
