If i was 42 when i had a total hysterectomy, how much longer will i have to endure menopause for?

Indefinitely: By total hysterectomy, i assume you mean the uterus, tubes & ovaries were removed. Surgical menopause (removing ovaries before menopause) can cause more extreme symptoms than a natural menopause. Some women never have noticeable symptoms of menopause, some have hot flashes & mood swings for 2-3 years, & some women have these indefinitely. Treatments are available, consult with your gynecologist.

Cold viruses: Not likely if you have a healthy diet. Colds are caused by viruses. Some vitamin deficiencies might make one more vulnerable to infections.