i am using the newest version of gzdoom tho? i downloaded gzdoom from the site today and am using a doom2 wad.
The fact that you jump too high makes me think that you've got a conflicting addon that replaced the player class and possibly other things, double check that you're not running the game with other mods or addons, if necessary, put gzdoom and doom2.wad in a new folder and let it generate a fresh config and try running the game from there