Totally got you, Tom
I was the dude over at SFBAAPS last year asking about college advice if you remember that:P haha I'm currently keeping a 3.6, but really need to get it up to a 3.8-4.0 to feel more "comfortable" when I apply to transfer to UCLA for Bio, or Human Bio, or Physiology:P Granted, I still have to take many, many science/math courses before I can even apply.
3.5 or higher is the goal, you are okay then. MCAD/DAT/LSAT etc, you will need to rock on however if you go those directions. Grad school/research science etc, then you need passion and interest in that area. People who like to solve problems, that are just fricking dang curious Georges........and are willing to prove their ideas, that's what will help the most.
Regarding motivation, never ever give up, the turtle beat the hare, tenacity beats brains. So persistence alone can accomplish great things.
Small steps will get you there, kick butt this semester. then worry about the next one later. Have papers due in one class from Hell? do the 1st one asap and stay on top of that, then after you get an A or B, start of the next etc.
Will it be hell at times? Yes. If you have to go through Hell, keep going
As someone who recently got his PhD, it is an endurance test. I'm a professional student. Still look like a student too, which at my age, is a good thing.
I also taught a lot at UF and at Community college, so I know what instructors are after, and how to study for things, how they make exams etc.
I am either very good at anticipating and calculating or very very very lucky.
Hopefully I'm very very lucky