Haunted by my past..

So as i was taking a shower, i just randomly began to think of how i had no childhood.. how i was a depressed and suicidal child, how i can hardly remember all the fun times i had but can vividly remember the days and nights i spent crying in my room feeling isolated and alone. As if no one could save me. I had flashbacks of getting bullied, of all the shit i had to put up with. And after the flashbacks, i felt nothing. I thought nothing. I could only stare at the wall with wide eyes. My body was cold, i had goose bumps even though the water was nice and hot. I then just turned the water off and sat in the tub, feeling vulnerable, having no idea what to do or how i feel. Am i depressed again? What triggered these feelings to come back? These are questions that i still cant answer. I am scared now. Vulnerable. When i got out of the shower i thought of suicide. How i could just tie the towel around my neck and in 20 minutes, i would no longer have to deal with anything anymore. That’s whats scaring me the most. The thing is, my life is the best its been in years, why do i feel depressed and suicidal all of the sudden? I cant comprehend it. Even though the suicidal thought was brief, i am still worried. I thought my life was finally at a turning point for the better.