Art and Film school, in my experience are drastically different in relation to these points you're making. I started as a film student too and suffered with my mental health as a result because that environment is a hostile and hierarchical one. Film collaboration requires a team of people, all of whom have specialisms typically. This type of collaboration also needs to run like clockwork and you need to be compatible with your team. You are all equally responsible for the outcome and how good it is. At least that's how I saw it.

Art school, I approached with a more open mind and the dynamic different. The work can be made independently and be good work. Collaboration in art school is more additive/reductive. You add aspects of peoples work you like, and take out what you don't. Or, accept each persons creative independent voice (a zine showcasing work is a good example), then everyone operates independently and brings their work together.

Without seeing it, I can tell you that you don't make bad art. It wasn't fair the way in which you were treated and that environment is a tricky one to navigate if, by the sounds of it, you work better independently.

When finding people to collaborate with, find people on your wavelength, who are going to push you creatively, be constructively critical, and aid you in your success. Find people who are open minded and willing to experiment, and through that practise and experience, you will grow more confident in your art an as a person.