Use fly-wheel diodes from output to clamp the voltage to VB. Across VB and VS a ceramic and elctrolytic capacitor.
I used the IR2125S and IR2121S for my H-Bridges. They have current control an error-feedback for processor control. So you could best ignore the CS input circuit in your case.
I also had to clamp the secondary ground to the primary with a high speed diode as well. I'm not shure about your IR2112.
You are probably lacking a couple capacitors and high speed, low voltage drop diodes to protect the outputs from spikes due to the inductances on the electronic board.