What if you don't give a damn about everything (the girl, parents, friends) and there is no desire to do something, even your favorite hobbies?

Contact a psychotherapist. And personally, ea not on the Internet. in order to understand what could be the cause of this condition (and there are a lot of options, from the usual blues to organic brain damage), it is necessary to be examined and pass at least a basic set of tests.

Without an objective examination and collecting a detailed anamnesis, advice is not only useless, but also harmful.

It happens. This decrease in "energy" is temporary in many people. Usually against the background of problems of fatigue, etc. But if you notice that all this will add a bad mood to the point of sadness ... then it is possible that this is how depression begins and you should contact a psychiatrist.

I wish you recover faster!

And what has come to the fore ?? What did they start thinking about all the time, where does all the energy go?
These are all psychological things. Try to remember when it started and what happened at that moment in your life.

I packed my things, bought a ticket to the sea and left for a month.
In order not to see or hear anyone, for I was just fed up with everything.
When I more or less rested from all the fuss and all the problems, I began to slowly do what I had long wanted to start. Finally, I dedicated myself to myself. Absolutely alone, I go to the cinema, to exhibitions, I walk wherever possible. And I like it. I like to do it ONE! I don't want to go home. But I'll have to, on arrival I think to disperse. And live the same way.
I think that you just got sick of everything just as easily. All people, all events. Sometimes you need to be alone.
And do what you want. Even if you just want to lie with a vegetable all day and do nothing. Film You Need Moral Rest.
A ticket to the sea, a backpack on a journey and go to the beautiful)