You can say this to someone who you've helped out a lot, when they do something like complain about you:

A: You never take me out to eat.

B: After everything I've done for you, you complain about me not taking you out to eat? I can't believe you.

Or if someone lies to you:

After everything I've done for you, you're going to sit here and lie right to my face!?

This is a really emotional, dramatic expression. Use it when you feel really annoyed or angry with someone.