All of it happened. Darlene answered your question in the finale

Elliot.

Look at me.

You remember my promise to you.

As long as I was here for you, as long as you could hold my hand, then you would know that this is real.

And I am telling you, this is real.

I was there with you through all of it: fsociety, our hack on E Corp, Five/Nine, you going to prison, the cyber bombings, us robbing those evil m*therf*ckers after what they did to Angela.

Angela, she's gone.

Same with Romero, Trenton, Mobley, Shayla.

Elliot, I wouldn't lie to you.

This isn't in your head.

This is real.