Should I seek help from a therapist?

When I was a young child my parents would leave me here, there, and everywhere while they went to bars almost everynight. I was always terrified no matter where I went cause I didn't know where I would end up that night. A lot of the time I was left with my older brother who always had friends over. They were all into drugs. It has been 15 years since these times and now I am 22 and I have always had this wierd dream/memory. Where I'm sitting in a chair and my brothers friends are watching me while my brother went to get drugs. There is 5 guys and me. I hear them talking about wanting . They look at me and the main guy pulls me over and says calm down i just want a kiss and that is where my memory stops. I have thought about this memory my whole life but lately it has been consuming me.My whole life since my childhood has been tough. I have been on antidepressants since I was a young teenager. I suffer from severe anxiety and am severely self concious of myself. I have an obsession with men who wear uniforms(cops,military,firemen) and also men who are taken. It has gotten so bad that i have actually slept with my best friends boyfriend. I feel dirty and unwanted is this all a cuase from my memory of my childhood in which I can't fully remember.Was I possibly molested by these guys and am repressing it....please help me?