Here is my 2 cents as an adult.
First off as an adult the only "judgment" I have is that you're in a lot of pain and no one around you gets it. Which that only makes it worse. (Yes I realize you pretty much said that already)

Second I am not going to encourage you to run away but I do want you to think about a few things. If you run away your essentially becoming an adult. By that I mean you are going to have to find housing. Housing costs money. You will need a job to get this money. You will need transportation to this job. This too costs money. Seeing as how you're in school you're only allowed to work so many hours thus limiting your income. You will also need to feed yourself. Something that once again costs money. I am not trying to scare you into staying, but I want to give you a small glimpse into "adult" life. If you do run away make a good plan. No I'm not saying plan how you're going to run away but what will you do after you run away. Where will you sleep, work, bathe? What about your education?
I just don't want you to end up in a bad place on the streets. So if you do decide to do this you need to be fully aware of what you're doing. All actions have consequences. Sometimes they are good sometimes they are bad do you just need to be prepared for either scenario.