Last night, I was out with my girlfriend and I think I experienced hypomania. We went out to to eat around 6 and by 8 I was full of energy, talking rapidly, feeling absolutely fantastic, and almost bought a dog and some birds (luckily my girlfriend was there to stop me). However, I'm not sure if this was actually hypomania because by 11:30 I was back into a depressed state. Is it possible for hypomania to only last a few hours, or is this just a normal teen mood swing?

Side Note: I was recently told by a therapist that I might be bipolar, however I have my doubts.