Yah I feel that, a bad teacher can really bring yer spirits down. :(
More difficult? I definitely think so. It's been so long that I can hardly remember Pre-Calc. But I remember learning a lot of basic things - exponents/logarithms, matrices, graphing transformations and such, introduction to limits..
In Calculus you really build on a ton of stuff you've learned from Algebra, Trig, Pre-Calc. There are so many little math tricks that you need to remember. And then on top of that, trying to intuitively understand derivatives took a long time for me, I was glad I got started on them long before I ever took a class on Calculus.
Honestly, my feeling is, if you can get past the first 2 tests in Calc1, it's smooth sailing from there. Limits really test your ability to do mathemagic. And working with the limit definition of the derivative is just so painful! :d
You certainly shouldn't give up though :D Study some stuff related to derivatives before you take it again. Make sure you can burn through the product rule, quotient rule, chain rule like butter, so you have ample time to focus on the harder stuff.