Genital herpes

I've just been diagnosed with genital herpes and have been prescribed aciclovir tablets 5 times a day. However I'm unsure on how I have got genital herpes as I've been with my husband a year and a half and have never had an "outbreak" my husband has had cold sores in the past but no for about a year then 7 weeks after delivering my little girl I'm covered in blisters and unable to sit properly. Is there anyway to soothe the pain? I'm in absolute agony. I feel so heartbroken. Does this affect anyone else on here any tips.

Thanks