Thank you for rescuing her. Fear of men is a commen fear for dogs, I think it's their deeper voices and the way the act. It doesn't always mean a man was mean to her. If you have men over for her to socialize with her, have them sit on the floor and ignore her. Maybe set a really yummy treat next to them, but ignore her. If she comes and gets the treat, then they can set out another one, maybe a bit closer to them, but continue to ignore her. Eventually, she will come up to them for attention. Have them give a slow pat on the back, not the head as that is scary and go back to ignoring her. After a while, could be days or longer, I bet she will start to crawl into their laps. Just have to take it slow and go at her pace.
Pam's Chihuahua Sanctuary