Possibly Mixed Episode?

Okay, so I've been getting treatment for... Some kind of psychiatric disorder for about a year and a half, mostly drug therapy the first half of that period and all psychotherapy the second half. Originally, it was straight MDD. Then the hospital said I was Bipolar. After that, the private psychiatrist said that it was probably Borderline Personality Disorder. Then I was hospitalized twice again, both times being diagnosed as Bipolar Disorder. With the hypomania and depression, I just consider myself bipolar, although nobody is 100% sure what I am. My therapist said he officially can't diagnose anything (since he's only a psychologist), but said that it was DEFINITELY some form of mood disorder. Over the past couple of months, I have really weird moods. I feel like I'm physically exhausted and I just can't do anything, like everything is a hassle, and I've been working about 10-15 hours a week and going to school 25 hours a week. But on the flip side, my mind honestly feels like it's hypomanic. I have so much mental motivation to do things, I NEED to start applying to colleges, but like I said, my body just doesn't want to cooperate. Does anyone know if this is possibly a sign of a mixed episode, since the ups and downs are sort of superimposed or am I just stressed or..? I honestly have no clue, and for the past month, I've been taking 200 mg of caffeine every day I work because all I want to do is sleep, but then when I try to sleep, my mind won't shut off and I end up sleeping either 8 hours (from like 1 PM to 9 PM) or from like 9 PM to 3 PM. I have Vistaril and Unisom to help me sleep, but I hate taking them because they leave me extremely tired the next morning. Sorry.. Got a little off topic. What I'm asking is, is it normal to feel hypomanic mentally and depressed physically or is that a sign of a mixed episode? Thank you for your help!

Stress can be a trigger. Mixed episodes are hell on earth. I am telling you it is really bad. I heard that many suicides occur during mixed episodes. FWIW

This doesnt sound like my mixed episodes but in saying that everyone is different.

I have felt like this before though, it was just a side effect of my meds really. My body was exhausted but my mind wasnt. We adjusted them and it is better now. Are you exercising?

I'm almost positive that stress is playing a part in it, but I can't do much about it. I can't quit work or school. I need to graduate to go to college, and I need to save money FOR college. And for a car too, but Eh. And I don't exercise like my doctor suggests (maintaining an elevated heart rate the entire time), but I do manage to walk about 4 or 5 miles a day, according to my iPhone's pedometer. I talked to a cardiologist who came to work yesterday (I work as a bagger for a grocery store) and he actually said that what was important was to just use muscles, not to do cardio exercise necessarily. But I can't exercise well. I did a stress test, and within 5 minutes, I was ready to pass out and my heart rate was over 200 BPM. It used to hover around 110 resting, but the Inderal I take has lowered it to about 80ish. But I don't have the endurance to maintain my heart rate.

Well theres your problem.