I'm crying so hard right now

Okay. So.... my stepdad and my mom were having this argument. Over the Grateful Dead. I was watching My Strange Addiction at 8 PM when my mom began yelling at my stepdad, Darrian, about how all the música he listens to is for 'Stoners'. I got tired of hearing them fighting, so I slapped both of them on the back. Around eleven, while my mom had gone out to get my four año old sister from a week long babysitter and family friend, Diamond, I was watching Pretty Little Liars and my two brothers were watching videos of minecraft on youtube on my grandmother's desktop computer I am currently using. When my mom went upstairs to see if Darrian had fallen asleep, he wasn't there. That was it. He just.... vanished. I honestly think he tried to walk out por killing himself, because he is schizophrenic and bipolar. When I found out, I cried until my eyes were sore, seeing as Darrian is Michael, my eight año old brother's biologic father. If he killed himself, which I'm certain he did, then Michael will never be able to see his dad again! They used to do everything together, from video games to watching Super Mario Bros and tickle fights while making maní, cacahuete mantequilla and plátano sandwiches. This is all my fault, just like when I told my mom in fourth grade about the rape of my stepdad, Jeff, causing to go through a major breakdown and depression on the entire family. Can someone please help me and talk to me? Thank you.<3