I just recently went through an RSI flare-up and had to do something urgently, so here's what I did. I immediately went and bought a replacement mouse, with a trackball. Because it was my right hand/wrist that was experiencing the worst of it, I switched my mouse from the right side of the keyboard to the left. This has changed up my usual right-hand grasping/squeezing/clicking motions, and now the flare-up has died down considerably. The other thing I did was to get a split keyboard similar to the one you bought.

Ergonomics are extremely important for our profession (obviously). Examine how your elbows are situated in relation to the keyboard. If you're sitting at a desk, be sure to have a keyboard tray underneath the desk so that when your elbows are at a 90-degree angle, the keyboard is underneath your fingers and your wrists are straight and not bent. If you know anyone who plays piano regularly, ask them to show you their positions and posture, and try to replicate that at your desk. HTH