I made another cut right next to the edge and went from there. Although that help me figure out why it was like that but I've moved past this point for now. Thank you!

Though now, I'm stuck at another point. Extrude was working fine for me and all and I don't believe I pressed anything I shouldn't have, but it doesn't extrude inward anymore. Both ways (z-Direction) extrude it outward starting from its origin, it starts going outward inside of within the object. I did the same thing two minutes earlier and it was fine. What could have possibly gone wrong?