Also, Mig, not to sound all bossy and whatnot, but if you are using any type of sugar substitutes, particularly aspartame, give it up for a while, perhaps introduce Stevie later, but many have claimed improvement from neurological disorders when they stop use... and sadly, aspartame is in a great deal of our food we "THINK" is healthy, like yogurt - even multivitamins.
http://www.livestrong.com/article/67657-aspartame-neurological-disorders/
Aspartame is found in products such as breakfast drink powders, breath mints, cereals, chewing gum, cocoa, coffee and tea mixes, frozen and gelatin desserts, multivitamins, sodas, wine coolers and yogurt, to name just a few.