Can't stop thinking about him cheating on me

Me and my husband have been together a year and a half , he has cheated about 3 or 4 times now, an constantly watched porn , he always talked me Into staying with him , I honestly think he's damaged me because now I can't even go to a store with him without thinking he's either gonna talk to another woman or looking at another woman's ass . the cheating stopped because he lost his job and I destroyed his phone he says " I fucked up I'm sorry it won't ever happen again " but why do I still get flash backs of the pictures and conversations he's had with other woman , he used to tell these other wemon I was bitch and say he was gonna leave me for them . I'm not sure what to do because I feel like I should trust him but I also feel scared and hurt .