Thyroxine after Graves disease and RaI?

I had RAI approximately seven years ago. Life subsequently has been a constant cycle of ups and downs. I take the generic Levothyroxine but with this as well as the Synthroid I need frequent dose adjustments (25-125mcg's with varying stops and stays in the doses in between). I'm told stress and smoking can be major factors in upsetting TSH (thyroid stmulating hormone) levels and was recently informed that soy negatively impacts the absorption of the medication. Soy has been a major aspect of my diet. I am currently spending a lot of energy searching and eliminating soy because of lactose intolerance and a mere tolerance for meat. Most labs report within the normal range but this may include high or low normals resulting in low/no energy and chronic fatigued -to- on edge, tense and sleeplessness. Life is still worth living especially in those far and in between days of what I call "the zone" (balanced TSH and medication). GOOD LUCK!