I felt sad from what I saw. Help me

My “narcissist ex” who discarded me..

Now he seems happy.. he’s posting how much he’s happy with his new supply.. lately all his social media is full of how much he’s Happy!

At the same time he’s buying “FAKE LIKES” on the pictures he’s posting..

Checked her profile she also buys “FAKE LIKES”

He’s 29 she’s 25.

I know he’s an ex for a reason, but for people who dealt with a narcissistic personality knows how much our healing is tough.. it’s not normal relationships..

So I don’t know how I feel, not anger because I know it was gonna happen.. but I felt so sad…😞😞

Don’t know how to deal with my feelings? Suggest me what to do? And how to move on faster.. am tired