You may be experiencing scar tissue. Whenever a part of a patients body has surgery there will always be scar tissue forming afterwards. This can be painless or it can hurt like heck. Depending partly on what was done and if nerves are involved. A cancerous tumor doesnt always hurt.

Im not completely certain what you are asking with "is it normal to have tissue left behind after radiation". Radiation will target the malignant tumor and kill the cancer cells. There still would be the areas near where the tumor was located that will be left after radiation treatments.

Recovery can take a very long time. It can be frustrating with the ups and downs and setbacks a patient goes thru. Try your best to focus on what you can control which is your nutrition and hydration. That is what will help you to heal and recovery from everything you have gone thru.

Hang in there, the worst is behind you.