There's nothing really good on today's market for a developer with
less than 2 years experiences, but I'm questionning myself, should I
quit the company ? Or is it the IT which does not fit my "naive"
expectations of the job , then quit IT ?
I completely disagree with the first part of this question. There are plenty of good jobs on the market for developers with less than 2 years of experience. I suppose it depends on what you view as "today's market" and what you deem as "good".
Before you quit the company, sit down and do some introspection.
Think about what you want out of your life, your career, and a job. Think about what is important to you, and what is not. You might even make a list and prioritize that.
Then, compare that to what you are experiencing in your current job and how it stacks up against the potential at your current company.
Once you know yourself better, and if you decide your current career path is lacking - then and only then do something about it.
If you should decide to change jobs/companies/professions, then interview hard to find the job that meets your needs. Once you have a new job offer and acceptance, then give your notice, serve it out, and leave professionally.
Whatever you do, don't just quit.