The symptoms do sound like bipolar disorder but the length of time that your episodes last for is incredibly short. Usually each episode lasts at least a few days (often much longer), and that is already considered ultra rapid cycling. There is such a thing as ultradian cycling, with episodes only lasting for a few hours or a day as you describe, but I think it's more rare. It could also be borderline personality disorder which has similar symptoms as bipolar, but with short mood swings like the ones you describe. I'm definitely not an expert and of course it would be a good idea for you to see a psychiatrist. It's a shame your mom isn't open to the idea. Are you still seeing a therapist? Maybe you could get her to write a note to show your mom how serious your situation is. I wish you the best of luck.