my boyfriend wanted to take a break from our relationship a little bit over a month ago a little bit before our one year. we got back together eventually and when I asked him if he did anything with anyone else he said no. today he confessed to me that he had sex with some random girl from his math class and smoked weed with her. I am  devastated and I don't know what to do. He says he's sorry and he wants to make things right but I feel like I'm going to have a hard time just feeling confident in myself and trustworthy in him. should i give him a chance?