I am worried about my relationship

Hey i am new here. I was worried so thought of sharing here. I read my husband messages talking to another girl,before that i thought he only talks to me like that.upon asking he said she was a colleague. Now i found another msg to a random girl on social media.

I have discussed this with my friend and she said it is normal for boys to do that and that i should not force him or else he will do more.

But this thing is bothering me so much. I feel as i am going through depression and anxiety that is the reason he is moving away from me.

What should i do?