Self Help is a notoriously crowded market, but I believe that I've successfully differentiated myself in a few ways. For one, most demographic data shows that millennials think/act/see the world differently, and I don't think there's much personal development stuff out there that caters to millennial attitudes and experiences very well.
We usually think of improving our life by adding stuff - like more things, more success, more friends. I think the starting place should be removing stuff - try a month without Instagram; try a week without looking at fashion pictures. See how that affects your life, your friendships, and your ability to focus on other things.