Neither o-chem nor physics are as difficult as people make them out to be. That does not mean that they are not challenging and that you do not have to study. However, I would recommend that you learn the concept, especially in o-chem. When I took it, many people tried to learn every reaction, and they would make endless amounts of notes. However, if you learn the underlying idea, then you can apply it to any circumstance. For example, if you learn the major idea behind an SN2 reaction then you can apply it to any set of reagents and make the appropriate products.
As far as physics goes, there are two types. One with calculus and one that does not involve calculus. If you think you will have a difficult time using calculus in physics then take the other class. You'll still learn physics, and it will look a lot better in you earn an A then if you take the one with calculus and earn a C.
One other thing that helped me in both classes is to read ahead of the teacher, that way I knew what was going on in the lectures. Alos, practice, practice and practice until the concepts are second nature. That's how I got through them and I did very well in both courses. Some people may not need as much discipline for they pick it up faster, but I wasn't one of those, the thing that made me succeed was hard work.
Bottom line: Don't go into the classes fearing them as so many pre-meds do. They are weedout classes for those who are not disciplined, not for those who are willing to work hard. As a matter of fact, I enjoy o-chem far more than general, and so may you.
Just remember, "there is nothing to fear, but fear itself."
Good luck and bust it out!
