Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.

If what you stated above is correct and you have ascertained the facts, then your husband is cheating on you, and he is guilty of adultery.

If he feels no remorse for his actions, and you have lost all trust in him, then you should reconsider your marriage relationship with him.

You have the Islamic right to seek a divorce from him.

For details on valid reasons for divorce in Islam, you may refer to the answer linked below:

Valid Reasons for Divorce in Islam

Almighty Allah knows best.