Why did you receive a Haloperidol injection? I understand that Haloperidol itself may have been used because of budgetary reasons, possibly to do with aged treatment-ideas in your location (haloperidol is an old, side-effects littered early antipsychotic, barely used in the USA and Western Europe, since here there are many more, much better AP's available), but there must have been a reason for this.
Do you by chance have a schizo-affective, or Schizophrenic-spectrum disorder? Permanent flattened affect, i.e no emotions and substantially less pleasure, is a feature of schizophrenia, and is often TRIGGERED by a psychosis - so, if you had a psychosis and then were given an injection with Haloperidol to bring you out of psychosis, then the current state you are in may simply be your NEW state - post-psychosis, Schizophrenia is fully realized and fully active - this state will then continously deteriorate unless given atypical, more modern, antipsychotics. (stuff like Quetiapine and Olanzapine)
Second-generation antipsychotics often do not have any effect on lessening the symptoms though, they just prevent further deterioration... The only antipsychotics with some evidence of effect on negative symptoms are the newest class, the third-generation antipsychotics, which there is some debate on whether or not they should even be called antipsychotics -
Aripiprazole (abilify)
Brexpiprazole
Cariprazine
Are the drugs in question.
Oh, and some of the 5ht3-antagonists - drugs like ONDANSETRON. These are drugs which are very selective, and have very good side-effects profiles because of it - they have traditionally only been used for the treatment of nausea, so the finding that they help schizophrenics with cognition and side-effects from regular antipsychotics is very new, and almost entirely from happen-stance, like so many other scientific findings.
If you had a psychosis, with delusions or hallucinations, then that may be the true source of your problems - psychosis have been shown many, many times, with actual images of the brain, to change the very structure of it, to rejigger how it works, permanently.
So, the blame may not be on the drug, but on your genes.
Luckily, if so, there are great strides being made, and there are now things you can do to improve the symptoms.
