Anger, Sadness, and Loss...Simultaneously?

[DJ33]

In the case of my breakup, she basically said she doesn't need me anymore and everything that I have done in the past for her is now meaningless. She basically left me for dead. I find it hard to cope with the sadness, anger, and learning to accept the reality. I know people say that there are 3 stages of grief but it seems like they are all happening together for me...