Good luck at ya!
I too went back to skool in January for the first time in almost 40 years...made me pretty nervous at first, but so far, it's been pretty...tough!
Only one class has actually been difficult for me...(psychology) probably because I have a lot of skepticism about the subject matter...but I STILL managed to pull an A for the semester.
Just remember, not only are you probably SMARTER than most of those kids going to school, you're probably better MOTIVATED than most of them too...it has surprised lots of them that I'm pulling almost straight "A"s...and I'm an OLD fart...
Go give then h*ll, and show em what you're made of!