I already had all the normal PSI stuff done (because who doesn't at this point) then added this mod, but I have no points to unlock the new levels.

Running a small servers for my friends and ran into the same issue.
used https://github.com/jaquadro/NBTExplorer/releases
to edit the players .dat file and worked fine.
Fields modified are in ForgeData: --> PsiData
SpellGroupsUnlocked:
deleted last line eidosManipulation
replaced lastSpellPoint: eidosManipulation with secondaryOperators
changed level: 28 to 27
changed levelPoints: 0 to 2

honestly I think could just get away with changing the levelPoints:

I am Having the same issue. I have tried using NBT edit to change my level and my level points, as well as deleting or editing my persistent data, but it always reverts to level 28 with 0 points.