Duuude. This happened to me. A week on non-stop crying at the drop of a hat. Two or three days ago it nearly turned to one of those painful screaming cries (glad I was alone). Now i'm having my first real manic episode in years. I put 300 xmas lights in my room, hung up my old fairly wings I found from childhood, carried like 20lbs of groceries on my back in a giant backpack, cooked dinner and lunch for everyone. My aunt mentioned that my demeanor had changed so drastically and she made a joke alluding to me secretly plotting to kill someone because I looked so chipper and active. I mean, I usually sit in my bed as it is, in the dark, with no hope. I feel like depression is my baseline emotion. I actually think I was having some really serious suicidal ideation before this.
Im on lamotragine
See your psychiatrist about a med adjustment as soon as possible. And it's perfectly possible to go from manic to depressed or depressed to manic. Do try to get some sleep if you can to try to stave off as much as possible in the meantime, but I understand that sometimes it's impossible, especially when you don't feel tired even though you should. Try to lower the amount of stuff going on around you to decrease stimulation. Lower television/music volumes, if not turn off entirely. Try to keep the lighting relaxed if possible.
Hope you start feeling soon!