you could take a look around
Nexusmods and/or the
Steam Workshop
make absolutely sure, that any mods you use is up to date,
and even if they are, it's very likely that we can't help you if there are problems.
(you may have to restart your game if your unhappy with a mod that messes with the level-up, they affect your saves)
I'm not aware of a console command to change the needed exp;
you could raise the general gameplay difficulty to "hinder" faster progress
not the same though :/
btw, I was dead wrong about the progression being non-linear
