I’m so lost

I broke up with my boyfriend of 3 years on Tuesday. I was so used to saying with him at least 4 days out of the week at minimum. I found out he brought a girl over Friday night & he cheated on me. I was at his place from Sat - Tues… The girl saw a picture of us when she was over & he put it down & told her I had died in a car accident & was grieving. I found out on Tuesday about this & dumped him. I should be angered and hate him for this but all I feel is hurt and loss over the fact that it’s over. I woke up in his arms on Tuesday and now it’s over?? I’m hurting so bad he & our memories are on my mind 24/7. I can’t eat or sleep. This is my first heartbreak and I can’t bare it.