Jealousy

How do you actually work through jealousy? To be specific, I know all the notions of:

1. You don't know what people struggle with behind the scenes

2. Comparison is the thief of joy

3. Take control of your own path

But seriously, how do you work through jealousy when life is straight up unfair? How do you handle jealousy because other people have had more advantages (financially, social norms)? When people haven't experienced adverse events that affect or lead to mental illness?

I know my advantages, I'm grateful for the wonderful things I have and I have things going in my life that I'm happy about. But still, I find myself feeling insecure, behind, straight up sad.