Hello This is the doctor reading your problem. I would like to start this advice by telling you should help yourself by getting rid of methadone. Methadone is a very harmful and life-threatening drug, with a great power of addiction. What is happening to you as far as I can understand from your message is that by injecting this drug in your veins your are causing vein collapse, a common result of chronic injections.The internal lining of the vein swells in response to repeated injury or irritation and the veins are blocked causing lack of oxygen and food supply in the muscles.This is likely to result in greater levels of permanent damage and you would require much more intensive and expensive treatment. Ulcers, Gangrene and local infections may result as far as thrombophlebitis very dangerous for your life. The most important is to try to get help by the others and let others help you by STOP using this drug. Best regards