you say you live in Italy, wouldn't it be possible for you to work part time as a waiter or something to gather funds while you learn in the other part?
you can find any book for free on the internet if you dig enough.
you seem to be caught up on wanting to get a job that offers the most money. salaries depend on the location of the person. if you live in silicon valley your salary is going to be higher than someone living in italy.
you say you've bought security books in hopes of bug bounty hunting but then felt like you're losing time?. it seems like you want to learn something fast to start making money. people won't hire you if you don't know shit about the things you're supposed to know. so taking the time to learn isn't a negative thing at all.
and then you say because of that you jumped into full stack development. but now you don't like it and you're asking us if you should continue. only you can answer these types of questions. people come from different background here in HN. some are db admins, soft devs , swes...etc nobody can answer your question.
my advice for you would be to try to figure out what you like the most, then try to build things with it. for example build a full stack application using any tech. anything to get your foot going to get a feel about the job. i also find it hard that you can't find a job for a tech other than php in italy?. i would assume so in a third world country but not in italy. also ever heard of remote work? freelancing?... etc. i feel like you just get too caught up on job opportunities salary and stuff that you don't get to focus on actually learning and improving. a lot of great people in web dev got there after doing shitty jobs getting garbage salaries. you have to do it because you like it not how many $ you gain.