Shame on your GP who prescribed Cialis. The GP should have talked to you to find out why such a young man asked for Cialis. Had the GP done that, you would now be under the care of a psychiatrist.

You describe a lot of depression, anxiety, restlessness, low self esteem, a lot of "existential angst", being directionless, but no paranoid delusions. It seems that you were drawn to ...

Don't use Cialis again - treat anxiety, which is the root cause of your issues (plus depression), and Cialis doez not treat depression and anxiety.