I mean, I think you more or less have it figured out, as you outlined in your post. Now you just need to do the work - whenever you feel the feeling of “I’m falling behind, its a disaster!” or “They have a new car and I don’t and I want it, its not fair!”, just take a moment (personally, I count 5 natural breaths as a convenient timer) to notice how the feeling actually feels. The physical sensations, the kinds of thoughts it brings up, the other emotions it brings up - be interested and curious about the feeling itself. The longer you can sit with the feeling like this - just feeling, noticing, being interested and curious - the more likely it is to feel heard and take its leave. And as you complete this practice over and over, the feeling is more likely to feel its mission is complete, and not come around to worry you.