Art design mainly includes: graphic design, environmental art, industrial design, fashion design, advertising design, drama art design and architectural design (these seven categories basically include all design industries). Baidu got it. See what kind of design you are interested in. Mathematics exercises people's logic, spatial imagination and so on. I think these aspects are still helpful to creativity, but don't imprison your own thinking. It will be better to have more contact with knowledge other than mathematics.
As for what major suits you, this is both mathematics and art design. I really didn't expect it. If you like art design yourself, focus on art design and find a job. You can sign up for an art class or something, study and find an art job. Mathematics is the basic thing, and learning it well will help. I think any two courses have something in common or want to make up for it. So give you some confidence. My major is also mathematics, and my major is programming. Some students also reported as artists.