Learn English – Term for someone who feel the need to learn

Hypercritical

FTD inclined to judge too severely; "hypercritical of colloquial speech"; "the overcritical teacher can discourage originality" also Excessively and unreasonably critical, esp. of small faults.

M.W says: criticizing other people or things too strongly or too often

A person who is hypercritical of everything one does, says, or writes can be extremely disheartening and demotivating. Think of a hypercritical parent, partner, teacher or manager whose exacting and severe behaviour can actively discourage initiative and creativity in their listeners.

I used to work alongside such a person. He was okay, and acted friendly enough but there was something about him which made me internally cringe whenever we exchanged words. Perhaps it was his excessive enthusiasm that I found most irritating, in any case I always had an excuse not to join him for a coffee.

There are some people you do not want to be alone with, and not necessarily because you fear for your personal safety but because they are unnerving, and you feel uneasy in their company.

Her unnerving habit of touching people she was speaking to

uneasy: awkward or unsure in manner; uneasy with strangers.