Do I need help? Should I reach out? *t

Lately aside from being depressed and suicidal, my emotions because I'm bipolar have been scattered. I am bipolar type 2 which just means I have little to none of manic episodes but longer sessions of depression throughout my life. I don't know or understand but my emotions today have been all over the place. For instance I cried while watching a specific show. I am not the type to cry but I did today. And then I noticed, when the show depicted sexual assault, I almost lost it. I felt pain. No, I have never been raped but- Looking back I was sexually assaulted? Maybe I'm overreacting but my tears don't stop. It was during high school at a family friend's house...the family friend had a son. And of course being a female I was never allowed to be alone with another boy therefore my brother accompanied me. We stayed over with her son, to keep each other company I guess. As well to take care of her house and wait till our mothers got home. I was sleepy and I was told if I wanted to I could sleep on her bed. So I did. I left my brother who was in the living room to fall asleep while he watched tv. I laid down and tried to doze off. But then her son came in. I don't remember much, just him suddenly hopping onto me and holding me down. I questioned him in whispers, confused and shocked. He then started grinding on me and it felt disgusting, wrong and weird. I have never been with anyone in any kind of way so this was a new to me. Despite me telling him to stop he wouldn't and I couldn't scream out. I tried pushing him off as best as I could, i didn't want to wake my brother. Prior to that people in school were always spreading rumors about me being a slut so of course if anyone saw, especially my brother, what would they/he think? He kept going, my hands pinned on the bed and i felt so filthy I wanted to cry. He then turned us around and kinda forced me to grind on him, I could feel his thing through his sweatpants and I hated it. I hated him. I hate him. He flipped us again so he could do the grinding because I refused to go along with this. After much struggle I pretended to hear my brother wake up and call for me. He finally let go as a reaction and I immediately ran off. I ran into the living room and pretended like nothing happened. I wanted to cry, scream and leave. But I couldn't. I've tried to forget this but it always pops back into my mind in certain moments.....I don't know what to do. Why am I crying so much? Why does this hurt?! I don't understand.