[Just found out today I have hsv 2]

I have been with may boyfriend now husband 15 years and just found out today I have hsv2.  I am 48 and have been battling with a lot of female issues the last couple years probably hormone related.  My husband does not show any signs of an infection.  Could I have contracted this 20 years ago and never given it to him? How could that be?  I have never had an outbreak before.  I have had times where I had some swelling over the past 5 years that was mild and went away right away.  But again I have been with the same partner for 15 years.  Could he have it and also not know about it and gave it me and then I had an outbreak? Needless to say this is a bad day for us both.  We have sex quite often and I have never seen anything on him.  Now I am wondering if he cheated and didn’t know he had it and had no symptoms and gave it to me.  I’m really upset.  I know it will be okay just more upset about if he cheated.  My doc is giving me Valtrex.  I’m already a week post outbreak and getting better.  Do I really need to take the medicine if I am basically almost better? I also only had one small spot but a huge swelling.  No other symptoms.  They prescribed 1000mg twice a day I don’t want to get side effects from this medicine and scared to take it.  I am also detoxing from estrogen dominance so I wonder if this brought the virus out of me and I never knew it.  Any insight would be most appreciated.