Islet Cell Cancer

Although I'm only 73, I've had this cancer since July of 2009 and was told "it would take me in 5 years." 28 radiation treatments, two cyclyes of Adriamyacin and Streptozocin, 12 cycles of Sutent and 1 cycle of Afinitor--I'm about ready to give up treatment.
Why? Because since birth I have had epilepsy and since 13 migraine headaches and Tuberous Sclerosis which I have on the brain--with depression. The fatigue and lack of energy has really taken its toll,even though I am retired due to the brain growths. Any ideas, as
Islet Cell is slow growing, mine is advanced due to size?