The problem and my work is attached. Vin is initially -5V for a long time before it switches to 5V at t=0. From that, I wrote down the initial conditions by having Vin = -5, replacing the inductor with a short and the capacitor with an open. That's how I found Vc(0) and iL(0). Vc forced response is 0. After writing down those two equations in the image, I got stuck. I'm pretty sure I made a mistake somewhere because K1 would be 0 which would make my complete equation 0.