You have neatly described your problem and the first impression goes in favour of some sort of chronic depression not severe enough, though. Definitely antidepressants (like Depsonil/Depsol-plus) must have helped you earlier. Tablets like Alprazolam are anti-anxiety drugs given for short duration and should not be taken without consultation and beyond a prescribed period. This medicine is habit forming and its effect goes off after certain time. I gather from your description that you may still be going through moderate degrees of depression. Seeking professional help for proper diagnosis and treatment (medicines and/or counseling / psychotherapy) may help you to overcome your symptoms. For further advice and suggestions you may contact any psychiatrist or the undersigned in person.