I am not sure that I can pinpoint your exact problem on the basis of a short letter. You may be dealing with multiple issues. First, you experienced the death of your mother and this may be part of why you’re depressed. Losing a parent is usually an extremely difficult experience. It’s possible that you have not effectively dealt with her loss and/or the traumatic way in which she passed. It takes time to heal the loss of a parent.
You also mentioned that you feel guilt over her death. I don’t know specifically why you’re feeling guilty. Since you did not mention why, it is difficult for me know whether or not your feelings of guilt are justifiable or inappropriate. I suspect you may be feeling guilty for using drugs with your mother, given the information you offered about your mother dying from a drug overdose. If this is the case, you must realize that her overdose was likely an accident and there was probably little that you could have done to stop your mother from using drugs.
You also mentioned that you used to be heavily into drugs. I am assuming that you are no longer using drugs so heavily. If you are using drugs in any capacity, your drug use may cause some of the symptoms that you’re experiencing. Depression and irritability in particular may be related to drug use. In addition, people usually use drugs as a way to conceal their unhappiness with life. Have you addressed the reasons for your heavy drug use in the past? If you are currently using drugs, have you explored why?
You asked about what you can do to get help for the psychological pain you’re feeling. You also mentioned that you have been to a number of counselors and that you have even sought the support of religious leaders for help with these issues. It’s encouraging to read that you’re open to seeking professional help. This shows your readiness for change.
My advice is this: keep searching for a therapist. There are plenty of ineffective and mediocre therapists available but with effort, persistence and patience, you will likely find a therapist who is truly effective. Search for a therapist until you find one that you like. Interview as many as it takes to find one you’re comfortable with. The symptoms that are experiencing are very correctable. With the help of a good therapist and your openness and readiness for change, you can likely overcome your depression and other symptoms.
Finally, I wanted to address an aspect of your question. People always think that others around them are so happy, and that they’re the only ones suffering. This is a common misperception. Chances are, if we surveyed those people, you’d hear that they too have some complaints. You’d find out they’re not “so happy after all.” Thanks for writing.