Do you find proposals stressful?
I did, too. For over a decade. But I figured out the reason I was having so much stress (and not having predictable success), was because I was thinking about proposals all wrong. I changed the way I did proposals and suddenly started to enjoy writing them, rather than dreading the task.
Teaching this technique to others, I know it wasn't just a fluke for me. Other people have in some cases doubled or even tripled close rates while reducing pricing pressure and stress.