When I get really stressed I spike high as well. Try to do blood tests frequently and treat accordingly. Trying to find ways to de-stress may help, although sometimes I think that advice is much easier said than done.
Also, if there are specific things that you know upset you, try to avoid them, whether it be conversation topics or an actual person. Personally, I've found a good cleaning/reorganizing sometimes helps. If I am stressed at work then I come home to a disorganized environment where I can't find things, I get even more upset, translation = spiking blood sugar.