Why am I never good enoguh? Why do stranger coworkers feel comfortable criticizing me?

Anonymous
there's many guys at my job who feel comfortable telling me what to cange about myself. One guy said i talk too slow and pause too much and he wouldn't wanna date a girl who did that cause she's weird.

Another guy heard me call another guy "bro" and asked why i called him that and said that its better to call men "sir"...

Other guys ganged up on me one day and said i should dress sexy and get my hair done wear makeup and stuff like that. One said someone might ask me out if i came to work in braids one day.

My question boils down to why am i never good enough for people? I try to be very nice and i dont want to criticize others because i think its very rude. Yet with how nice and polite i am, its never enough for anyone. Its like nothing i am or anything i do is not enough.
Why am I never good enoguh? Why do stranger coworkers feel comfortable criticizing me?
5 Opinion