Thank you for your inquiry,
Based on the information presented, your chief complain pain and medical background, it seems you suffer from a chronic illness complicated in some aspects.
Hopefully, you had a successful resection surgery 3 years ago. Since you have a
severe pain now, I think it is a good idea to control your pain as soon as possible using modern methods such as Lumbar and
Celiac plexus blockage conducted by a regional anesthetics expert. These nervous system blockages decrease your pain significantly for 6-12 months. The blockage performed for the dorsal rout of nerves at the level lumbar (Known as lumbar plexus) can be completed with insertion a catheter (Known as continuously patient controlled regional analgesia) to complete your pain reliever method.
Another method is to use non-opioids drugs painkillers, which are well known and available in market now, this requires to apply it from a pain clinic specialist. I also recommend you consult with an
oncologist to supervise the progress of your previous malignant
tumor to prevent unforeseen events in future.
Hope you get well soon,