Should I forgive him?

I broke up with my boyfriend and as soon as that happens I see a photo on snapchat of my boyfriend and my BEST FRIEND together eating ice cream. I can tell you now that my bf and my Best friend were not very good friends. Apparently she was just driving past but I think that is absolute bullocks. I cried for 3 hours straight and thats not an exaggeration!!! I was texting my best friend saying that I was annoyed and she called me. As soon as she picked up I burst into tears and just hung up. But that got me thinking. My boyfriend didn’t cry or anything. One text from him to her and she was over there at the speed of light but I get 1 call from my best friend that I spend everyday with and suddenly I am a bundled up piece of shit to her. I am so annoyed that now I can’t even sit in the same room as her. I refused to go to classes after that because I was in so many with her. This affected my GCSEs. He literally said to me that he almost broke his hand and I responded with ‘I almost killed myself’ (I’m fine now. Do not worry about that) and he said I had no idea. He now wants to date me again but I just don’t know if I can forgive him of what he did. It ruined my life. He didn’t do much but the fact that he took my best friend away from me almost cost my life. I have talked to him and him and her still talk but I don’t want them talking. Should I date him. Or not? I don’t know if I should forgive him!!!! This all seriously made my depression worse!!!!! HELP!!!