With the breaker on said circuit live and active, I noticed the neutral for that circuit was loose. Took it out from its termination screw to check it for corrosion and it sparked. Put my meter across the said neutral and the ground lug and was getting a voltage reading of 120ish.
This so far has not been a breaker tripping issue so I'm wondering if I'm getting backfeed or is something else going on?

That is exactly what it is. It is being backfed through what ever load is on that circuit.

NEVER EVER, EVER remove a neutral with the circuit live. Besides potentially damaging whatever is connected to the circuit you could easily find yourself DEAD!