Insight re feelings at the end of a relationship

As I've mentioned, I'm in the process of splitting from my husband. It hurts so bad. We started dating in 2011. Married in 2013. I know it's for the best. He knows it's best. We want to stay friends but I'm angry and I'm hurt. I feel more free and I've fallen for somebody else, but it still hurts so much. Some days seem worse than others. Like, one day, I'm happy to have the freedom. The next, I'm thinking of all we've been through and all the time and little gifts and gestures and feel so alone. Is that normal?Do you ever stop thinking about someone? Does the sting ever fade? Do you ever stop feeling angry and hurt? Am I going insane or is this normal? How long does this last?Just give me some insight, please. I don't know anyone who's gone through this and I have no idea what I "should" feel or do.