The punch in subs comes from four things.
You can lengthen or shorten the pitch decay envelope to give the sub more of an initial punch.
Try bringing down the sustain on the amp envelope while lengthening or shortening the decay.
Try boosting the sub frequency or fundamental, often they get reduced if subs are being limited or distorted.
Transpose the MIDI up and down until you find the key that feels most present and punchy.
The above parameters should be adjusted and tweaked while you listen carefully and pay attention to the changes and how they sound. Remember, it takes years of practice to develop and ear for music production and sound design so don’t get frustrated if your sounds aren’t as impressive as you expect them to be. Just keep practicing and you will improve.