I discovered my husband with a secret cell phone to contact a woman?

[Kayla]

I recently found my husband's secret cell which he was using to contact a female student. He was an instructor at Sanford Brown University. He had access to student phone numbers and was calling this female student 7 times a day for months. I did a reverse phone number search and spoke with the student who said she did not give her number to him and he was calling her and asking for dates, she was declining the invitations, however, she did not tell him to stop calling because she needed a reference from him for a job and wanted to stay on good terms, once she got her reference, she had no need to speak to him anymore, however he persisted in calling to ask her why she would not meet him. I was told by this female student that he was bad mouthing me too. She told me to be careful and that he was my enemy in reality. At that same time he was stealing money and hiding it in my son's school locker too I asked him to sign a separation agreement because we have 5 children and I feel i need to protect us. I had no idea my husband was living a secret life and he was doing this to me. I also informed the school that he was abusing access to student phone numbers. What should i do? All i was doing was taking care of the kids doing their homework feeding them, working out of the house, selling on ebay, etc and he was doing this behind my back. please give me some advice on what to do