Husband watching porn again

My husband and I were friends for two years and then dated for two years, the last 6 months we were engaged. After about a year of dating, he told me we struggled with porn and he didn't want to watch porn. He had some support and he said he stopped watching it. We have been married for 4 years now and I saw some porn on his phone. I talked to him him about it and he said he started a few months ago. It has been a stressful time, which I understand. I told him how I just want to support him. He asked me to check in with him on how he is doing and I do, but I'm realizing I don't trust him. I do view porn as cheating.

I feel like a crazy person. I have looked into parental control monitoring apps. I want to see if he has really stopped. Am I crazy? He lied before and maybe he needs more help than what I can give him.

I know there are those who think watching porn is fine, but I personally think it can be harmful to a relationship and my husband said he doesn't want to be watching it either so if you don't agree with that please don't comment. Thank you!