Do yourself and the world a favor. Go to the school nurse, a teacher or the principal, and tell that person you are being abused in your home. In the US that person must contact child protective services. Remind them of this if they try to blow you off, like it is no big deal. It IS a big deal.

Then tell this person that you have become the target of bullies at your school and you need for it to stop because it makes you think of killing people.

Then call your doctor and say you want to discuss the prescription she or he wrote for you. YOU are the patient. Not your mother. You have a right to understand what has been prescribed for you and why, and you also have the right to discuss alternatives to simply medicating your condition. Make sure you tell the doctor that your mother has physically abused you.

Now to some practical stuff. You don't say what books people are touching. Are they class-issued textbooks? Don't keep anything important between the pages. Don't lay any personal stuff out that others can look through if you are not prepared in the short term for your bullies to continue to use this to bother you. They'll continue as long as the school looks the other way and you react.

There will be bullies everywhere you go. The trick is to learn to avoid them, not give them any power, and not allow yourself to be drawn into their evil need to harm others. Walk away; turn away, quietly say "knock it off", ignore them; figure out which method works with which bully. They can't victimize you if you stop considering yourself a victim.