I think I am bipolar,How do I becomes more stable with emotions?

My mother is bipolar, and i think i might have it as well. Sometimes I am as cheery as they get, people say i always smile.I will be extremely overjoyed. But they havent seen my "other" side .. and i am extremely upset and sad and dreary and introvert. I loath that part of myself.... (as anyone would) ..... and i am to scared to tell anyone, my step-mom and my father wouldn't take me seriously and my mom would understand but not do anything about it. And i feel like if i tell a docter or an adult that they would send me to a therapist or something (which i have never been to before) and just thinking about that puts a giant lump in my throat, because that mean i am "messed up" or not right or not as i should be... a dud.... I dont want to be the dud.....i want to be normal!....I want to not be like i am but i DONT want to be put on pills or go to a... therapist. What do i do? How do i fix this without the use of those things? Please help..