I just found out my husband cheated on me while we were dating

My husband is in the army and we started officially dating in November 2017 he later proposed on December 2018 and we got marry in June 2019. I know it looks like we rush everything but we already knew each other since 2016 and we were on and off trying to date but it would never work out because of distance but then we decided to officially try it. Today I was trying to look for something in his laptop and I came across with messages from all 2018 where he was talking to others girls telling them they were cute and he couldn’t wait to see them, set up dates and a lot of flirting. Two of the girls that really hurt me was one girl he invite over to his apartment several time and the other girl got pissed at him because he kept forgetting to text her back so she told him he was a horrible guy that was cheating on his gf *me* with her and how they exchange pictures and he always gave her hopes.

I tried talking to my dad and my sister about it and they both told me I should confront him about it, but not divorce him because our marriage just started and what he did was in the past. I just don’t know what to do or think.