Is It Safe To Take Clonazepam For Anxiety?

I have been in treatment for pain resulting from degenerative disc desease, arthritis, raynauds desease, myofacia pain syndrome and fibromyalgia. I have been going through a lot of UA s and accusations of being an alcoholic and using methadone (unprescribed). I am a 60 year old woman and have been on social securtity for 9 yrs due to these and emotional difficulty that prevent sleep (diagnosed with PTSD and anxiety disorder). I worked for 40 yrs as an accountant. My physical illness for the most part and my emotional illness is from physical and emotional abuse endured as a child and a marriage of 15 years. I took clonazepam for the anxiety, but it was withdrawn a year ago. I take 30mg oxycodone three times a day,but they are now threatening me with dismissal due to the methadone reading in my UA. what are the FDA rules on pain medicines like mine. I cannot endure this stress for long and cannot deal with the thought of no way to reduce the pain. I am not an addict,nor have I ever been on unprescribed medicines.