Is it possible to make normal pins act like ground pins?
No, it's not going to work - even worse, you risk frying your Arduino -, for the following reasons:


The Arduino data pins can't source (neither sink) enough current for that to work.
The inductive kickback of the motor could fry Arduino pins.


The right way to do what you want to do is using an H-bridge controlled by your Arduino data pins. There are lots of Motor Driver PCB modules for Arduino (most of them based on the inefficient L298 driver IC, which you should ignore and look instead on those based on the TB6612FNG driver IC or similar, because it would be a far better solution) that implement this function.