Art classes can be very challenging, especially if you have a lot of studio classes in the same semester. The best advice I can think of is to be mindful of yourself as a student of art-- meaning the more receptive you can be to learning, the better. Your efforts will not always earn you perfect scores. Just remember that you are making student work, and don't let it get you down. Until the day we stop producing art, our best work is always yet to come.
Also, you will have a lot fewer stereotypical angsty tussles with your art profs if you are willing to hear their criticism to the last and file it away instead of arguing, even if you disagree. My biggest regret is not being a more receptive pupil. I had some very charged exchanges with my professors, and I look back on those moments with shame at how headstrong I was.