I think you are being too hard on yourself and too unrealistic. There is no "should" about receiving A's and there is no need for receiving A's or harm/badness is receiving an F. You are working on your life/problems and that's good. I got an F because I withdrew from a class incorrectly and it was around/affecting my GPA for so long the course I got an F in became wholly obsolete! There was no such course when I went back to school to take again to "fix" that grade with. But I was not interested in that course and had changed my interests by then (like you have now) so it was wholly germane. I got straight A's in my core courses and went to grad school fine, etc. Concentrate on the courses and your health and do the best you can and let the grades sort themselves out; they are not what is important; it's like saying you only want X amount of money and not a penny less or must have multiple plastic surgeries to look a certain way, it's all external to you and your life.

Your job at the moment is to get healthy. If you can withdraw from the course okay, great, if not, do it anyway. I would go to the professor and discuss what is going on and ask his help (getting an incomplete or WP) and not mix the two, what courses you have changed to out of changing interests with your health/depression issues.