I’m so sorry that you’re going through this. You need new friends. The ones you describe aren’t friends. Friends don’t hurt each other. If you’re in high schools you, can you join clubs that share your interests? Technology, gaming, science, pets, even gardening are always available. In high school I was involved in the school newspaper and yearbook. My friends there respected me for much more than how i spoke. You need to develop confidence that you’re more than your stuttering. You’re still young enough that speech techniques and self-help could make speaking easier. . Whatever, the ‘friends’ that you describe aren’t good for you. Anyone who brings you down has their own issues. If you can change who you associate with you can see yourself in a new way. Again, the quality of the fish that you catch depends on the quality of the pond. Find good ponds and you would find good fish. Friends are there who will value and support you, never laugh at you.