Being lower middle class is that place where nobody helps you with anything. You're too rich to get help from state, and too poor to have any easy money like rents, interests, whatever. Being next to the poverty threshold it's a terrible place to be.
Being lower middle class is to know that a friend, to be able to get some state money during college, pretended to live with a grandmother without his parents help and regretting not having done the same.
But I don't remember being stressed about what others thought about me and that made my whole adolescence beautiful.
One thing that you fail to acknowledge is that in rich countries smart poor guys don't get girlfriends. In East Europe being poor is/was considered normal, and as such, getting a GF in that situation is much easier and it will make wonders to your self-estime. This will hardly ever happen in the western rich world: I was luckier because I used to eat at my ex girlfriend (present wife).
I think that my years of poorness increased my motivation and desire to succeed in life drastically
No, it didn't. You just hit a jackpot: niche IT for a foreign company. Probably the best you can get worldwide (as an employee).
Being lower middle class is using a HN throwaway account because risking to be linked to this purge doesn't help at all.
Being lower middle class is 4.5h of daily commute to public college (despite having best grades in your high-school) while being told all the time that you're a priviliged.
Being lower middle class is your friend suggesting to use his adress on your CV.
Being lower middle class is hiding your hometown from your coworkers and having them smirking and condescending when one day you can't evite anymore and show it on Gmaps/street view and regretting that you didn't show a random location.
Being lower middle class is being ashame of bringing friends home.
Being lower middle class is having friends scaried of coming to your place.
Being lower middle class is saving all pennies you can because you are terrified of getting poor.