I think you will have less gray hairs once your realize using any indicator or tool, especially by themselves, is subjective. They are nothing more than different calculations of the same thing: price action.
In my view, the fibonacci retracement tool can be even more subject because you as the user, must pick the swing high and swing low. In trending markets this task may be more obvious than in the range bound markets. Also, the definition of a swing high/low will probably differ from one trader to another.
With that said, I love using fibonacci's and I think it is a very powerful tool for the way I use it.
First, I view the area from 38% to 61% as a potential S&R zone and reversal area. While I've seen it time and time again, certain levels can turn the market around, but I do not like to base my entire position on one level.
Then I ask myself a few questions:
Is the pair trending or ranging?
What is the overall sentiment on each currency?
Have the fundamentals changed or not?
Are the levels lining up with psychologically significant levels such as '00 and '50?
Was the recent swing move fast or slow?
With questions like these I determine the
probability of a profitable trade and if its worth the risk. And that's basically how I view Fibonaccis.
One last thing, I bold "probability" to make one last point that may save you, and hopefully others, a few gray hairs ... The day you realize and accept that there are no certainties in this business and in the markets, and when you build your strategies and money management system around that idea, is the day you begin your journey towards stress free trading.
I hope this helps