Would you get a divorce if you were me?

My husband and I agreed his mother was a psychopath and he said he regretted asking me to see her becoz she was constantly hostile and belittling me and said lots of disrespectful remarks. She never said thank you once although my family and I took her to sightsee around our city the whole day for many days. She’s also influenced and brainwashed my husband to mistreat me in many ways, including lying and deceiving me on several occasions. He realized he listened to her too much and she’s only been looking to destroy our relationship. Anyway, before we had children, my husband agreed that he wouldn’t let her have contact with them because I’m afraid shes going to brainwash or manipulate them and turn them against me or be mean to them. I thought my husband has kept his promise. I always trusted him. I agreed to have our son to abroad and live with my husband alone for four months during Covid time becoz it would take me too long to get my visa. I didn’t want him to delay starting school. But I just learned from my son that during the time we weren’t together, and he was alone with my husband, he had him talk to his mom several times. My husband never told me and always said they had never talked. I felt so betrayed. It was also my sister that paid for our sons visa and airplane ticket. And she also felt betrayed because he took the opportunity to let him talk to his mom behind my back and she knows this is unacceptable to me. When I confronted him, instead of saying sorry, he said what I did was wrong, to not let grandmother talk to her grandchildren. But this is what we agreed on together, this is what he promised me. Now that he changed his mind about it, it’s suddenly all my fault. I felt so mad at him. We’ve been fighting very hard. This is also not the first time he lied or hid things from me. He did this to me many times in the past claiming that it was from his mother’s influence. I can’t believe he did this to me again. This time, he insists it’s not from his mother’s manipulation, he really thinks she should have the right to talk to our children. What would you do if you were me? I want to forgive him if he at least apologized. But he thinks it’s all my fault and talks as if I deserve to be betrayed :(