Do I convalidate my marriage?

This is complicated and I need advice. My husband and I have been together 10yrs. We had our daughter 9yrs ago out of wedlock, then our son 5yrs after that. After 7yrs of dating we (I, bc he always wanted to but I had thought marriage was “just a paper”) decided we wanted marriage and did a civil ceremony. We had our 3rd child shortly after getting married. Neither one of us was religious. We were both baptized in the Church and received communion as kids but that’s it.

1.5yrs ago I had a radical encounter with Jesus. Eventually that led me home to the Catholic Church and I’m currently in RCIA. I was eager to convalidate my marriage.

HOWEVER, 2 months ago I found out my husband was having an affair the last 1.5yrs. The day I found Jesus was the day he cheated on me…

I talked to my priest and he basically said hold off on getting married in the church and also suggested I talk to a lawyer about my situation.

My goal is to reconcile with my husband. He is repentant, he even went to confession after and started going to church with me (I’d still call him agnostic though),but I am willing bc of his remorse. I believe God wants me to stay with him. But the thought of marrying this man in the Church and this agony possibly happening again without the option of annulling it terrifies me.

Is this mindset wrong? It feels like I’m one foot in, one foot out now. Should I wait to convalidate? I don’t think I’ll ever be excited about that like I was before.