I agree that gum should be allowed in schools, but you have to take into consideration that there are some people who would abuse this freedom. Sticking there used gum to walls, throwing it onto the floor, or mashing it to the underside of a desk. This would be quite a big mess. Then there might be complaints from janitors who get on there knees all afternoon scraping up dried gum some of them might even go on strike, then there wouldn't be anyone to clean anything. In conclusion I would really enjoy this idea, its most likely not going to happen.
Counter Argument 1:This can easily be avoided by not allowing people to stick it anywhere and make them clean after themselves.
Argument 2:I have Autism (High-functioning) and suffer from Anxiety disorder (linked to Hyperventilation Syndrome), ADHD, and OCD at the same time and chew gum. When I chew gum, I don't suffer these conditions. Why force someone to suffer these diseases when gum can solve these problems?
Well, its not that simple. Its hard it always see who is making the mess. There are usually too many students in a school to keep watch over them 24/7. I do believe however in your situation, you should be allowed to chew gum if it truly helps you either focus perform better on test or even just regular work.
Counter Argument to Counter Argument 3: would love to think of this as the only place where students would chew gum, but sadly students might go outside of class and do the same thing I explained in Round 1.
Argument 5: I still agree with you that chewing gum could be helpful, but there are just too many irresponsible students to make it a nation wide freedom in schools.