I believe in the expression "what we think about expands," and although it is very difficult to do at times, I think it is important to at least make the effort to chase away any negative thoughts. Literally chase or force them away and/or replace them with healthier thoughts. This could be compared to when someone wants to go on a diet and they replace any candy bars in their home with fruit and vegetables. So, when you have thoughts that you are "nobody," try to force in a thought that makes a "correction" to that thought. So, for example, think about all the times in your life that you were helpful to another person or things that you have done during the week that took great effort, yet you were able to accomplish your task anyway.
You might want to ask your former therapist if you could go back less often than before (for example, every other week as opposed to weekly if that is what you were doing previously). In addition, I would tell any nosey relatives that you wish you did NOT have to take pain medication and that you hope that you can soon reduce your pain medication and maybe even some day get off of it. But for now, this is what you need to be comfortable and that you are grateful to the doctors and medical science that this treatment is available to you. You might add that no one in their right mind would wish to have pain daily and be forced to take medication to treat it. Remind them that you are trying the best you can under very difficult circumstances. If they can not accept this, so be it. Continue fighting for disability if you are unable to work, and see an attorney who specializes in this area if you continue to be denied. Fill your heart and mind with uplifting literature like books, music and programs and do your best...fight the good fight...to push away negative thoughts and replace them with strong ones.