Is it mental or physical? and how do i make it stop?

Background: I'm a junior in high school, on Adderall for ADD and recently started Celexa for anxiety. I generally have a highly irregular sleep schedule and have often used Adderall to allow me to stay up all night working. The past few weeks, however, I...

have not been staying up all night or taking Adderall at irregular times.

Issue: So, it's a four day weekend and I have tons of homework/studying. I'm trying to redeem myself in school and this is the final stretch, and my last chance to pull my grades up a little. Thing is, every time I start studying I get really really exhausted. A lot of the stuff I'm having to teach myself since I've been absent a lot. So, I'll do one trying math problem, and then I'll be completely drained. And I have A LOT of catching up to do in math! I have no idea why my stamina is so low, does anyone have any suggestions for getting through at least some of this work without falling asleep? Does anyone have any idea what exactly the root of the problem might be?

Okay, well it seems like you're taking way too long on your homework, however you mention that you have had to teach yourself? Thats why! Its extremely hard to have to teach yourself a subject, especially math for that matter because the teachers teach you the tricks and how to get the answer with the least amount of time and the most effectively. I understand what you must be going through, I've had to teach myself stuff too and it isn't easy, it takes a lot of time. I just think you need to be patient. Keep on doing what you are doing except maybe make a time schedule. Tell yourself, I will spend no more than this much time on my math, if I can't complete this math problem in this many minutes, I will move on. Then when you get to math class ask your teacher to help you with the ones you couldn't get fast enough. Trust me, this is the only way you can get to all your subjects in time, with a time schedule. Also if you feel drained out or exhausted, take a 10 minute break after an hour of studying and this really helps in picking up your energy. Eat a snack, drink something, or even just stretch or use the bathroom. You will be surprised at how much energy this will give you. Best of luck.

I just hope and pray you've been diagnosed properly and not put on a road you may not truely need - sure hope that isn't the case - I'm older and I just wonder how my generation made it through unmedicated and faired well...I wish you the best !!