If memory serves, and google says it does, the temperature of the sun is around 15 million K. I'm not gonna bother googling it, but I'm pretty sure 15 million K is lower (much, much lower) than absolute 0. So the numbers flat out don't work.
A. The reaction rates differ by about 16 orders of magnitude: The sun is going to run about 10 billion years with no refueling. A Tokamak fusion reactor would run for a few seconds or minutes.
2. The sun is using a completely different set of nuclear reactions with completely different fuel. There is no direct comparison anyway.