Hey there. Due to the way power levels in the game have shifted, any Guardian below 1,600 power is technically 'below 0' and will be unable to damage anything. Normally items get bumped up to at least this new power floor each time the levels rise, but really, really old items may not be. From what I can see you still have your old character who was made in 2018, and they still have the really old gear on, the kind of stuff that didn't get boosted. You can't delete your only character, and you don't show as having any deleted characters, so maybe you misunderstood what was happening there. Create a completely new Hunter and try playing on that instead. That should have a viable power level and then you can delete the underpowered one.