Previously used portal to nether does not load and falling out of world when logging back in.

I went into the nether portal at my base, which I had used multiple times, and it was not loading. I closed the game and when I logged back in I was falling out of the world (not sure if I was in the overworld or nether at this time) but the x and z coordinates were the same as my base. Also, I just kept falling I got to a y level of -3000 and was still just falling.