Questioning regrets

I don't really have time to blog, but I need to get this thought out of my head. I can't concentrate on studying with this regret.

I have the same ochem professor I had last year; the same ochem class I withdrew out in the winter. Midterm II is next week and last week would have been the point in the quarter when I withdrew out in the last year, week 5. My ochem professor's exams have gotten a bit tougher. So, here is my regret. Could I have hung on to another 6 weeks and gotten an A+ in ochem? Did I ruin my chance of getting that easy A? Did I really need to withdraw, since I was able to survive for 6 weeks until I actually got the treatment? I don't think I could have because my MG was taking over. I seriously couldn't concentrate on studying then. If I know this, then why am I still beating myself over doing something in the past I can't undo? Isn't it enough that I came back to Davis and I'm getting my life on track? Haven't I learned that regrets are never a good way of going through life? I think I'll beat my self up if I get anything less than an A in ochem and physiology this quarter. Maybe I could have channeled my focus on my class a little more last year, but I'll never know now. The only thing I can do is focus on what's important now, and that's studying like mad for the upcoming midterms.