Hi Dt122 and welcome, sorry for what has brought you here but so many of us understand your confusion and reluctance to just forgive and forget.
I think your instinct is telling you a lot, like NOT to trust him and when we find it hard NOT to trust someone we love the entire relationship changes forever.
Is he clean/sober today? And if so, how do you really know he is and not lying to you again? If he is clean/sober what kind of a program is he working to help him remain that way?