Husband and FB messages

Back in March. My husband was messaging an old friend. Said they missed each should meet up blah blah. Fine. Wasn’t too much of issue. He’s been hiding the newer ones but shows up on our iPad. Today, she messaged him saying a bunch of stuff.

All I can sit and wonder is what I did wrong and why I deserve this.. he’s my first, everything. I’m so broken. Especially my mom kinda did the same thing to my dad but with a guy from a different state for years.