What Causes Severe Pain In Muscle Behind The Ankle?

Hi I had a fusion surgery in 2011 on my S-1 and L5 vertebra. In 2014 they removed it because was still in pain and they thought that was the problem. It did help some the pain in my calve and back ankle muscle in gone. The muscle behind ankle has been hurting again. Before the second surgery had some nerve block shots and one time burned the nerve as they said. All this did no good. On my right side of back they say is my SI joint, but may be higher than joint I don t know, the bones stick out farther than left side. That s where yhe pain comes from and I hurt on the side of the upper side of my leg. They say it is caused from SI joint. They say only thing to do is fuse the SI joint together, but they say the success rate isn t great from that. Im still trying to work, I have a job were I can walk and sit. I am in pain all the time. Been taking pain medicine for several years and I hate that my body depends on it, but don t know what else to do. Some say get on diability, but I don t want to quit work if I don t have to. That doesn t pay the bills so well either. Im a very active person and that s one reason Im in the condition Im in. Sometimes I get depressed and don t care to live. I know that s wrong and selfish to my wife and family, and a sin against God. I am just hoping that I could find something that would help with my problem and try to get off the pain med to live a sober mind life. Thanks for your concern. Marty