He is still alive, moves and he looks fine to me expect for the fact he is a bit pale. I forgot to mention that he didn't loose weight in these past 1.5 months.

I'll keep his humidity at higher level than usual, just in case.
I have a vet I can visit (he knows my snake) and he has his clinic only 30 minutes away from my house if I take the train. Luckily the outside temperature is perfect for transporting him.
Since tomorrow is a holiday (Corpus Christi) which is why everything is closed, I'll try feeding him on Friday with a mouse and then if that won't work I'll take him to the vet.
If I'm lucky, he is just fasting.

Thanks for the help. I'll keep you updatet on his progress.