I don't think you typed what you meant to say. Read it again. Raise ISO to lower shutter speed.
The OP needs a faster shutter speed, not slower (which is what I think you meant to type). Raising the ISO would also raise the shutter speed, not lower it.
Technically, the shutter speed is lowered, not SLOWER. Lower means more towards 0, where a faster shutter speed will be closer to zero than a slower one.
Faster shutter = lower shutter speed = closer to zero
I mean what I type and I type what I mean