I have the same problem. Me and my doctors finally connected the dots and figured out I was bipolar (that is I stopped denying it) and now I worry about telling my friends and family. They don't know how much of a problem this is for me and I doubt they will be supportive since they've always known me to be depressed most of the time and assume my manic episodes are me just being my true self, which is artistic and clownish. I don't think either are the real me now. It's like I'm 2 different people at opposite ends of the spectrum trying to compensate for each other. Somewhere in between must be the real me. I try to hide my emotions but it's getting harder in my 20s and likely to only get worse. I'd say you should talk about this to your therapist and if he doesn't want to ask you questions or be supportive about why you think you have bipolar, go to a psychiatrist who is more experienced with such things, tell him/her your concerns and at least you can receive some treatment/meds that will help.

I too was ADD in my childhood, but only sporadically where I got punished by teachers for being hyperactive. I guess this was before they put everyone on Ritalin and most of the time I could stay in my seat, I just fidgeted a lot and was easily distracted. I'm sure future studies will confirm that ADD and ADHD can be early warning signs for bipolar or other disorders in adulthood, but I'm no expert, so we'll wait and see.

Hang in there. It's better to reach out for help from the proper experts rather than struggling alone. You can decide if you want to tell your mom after you get an official diagnosis, that way it can't be as easily dismissed.