Thats internet for you. I have 4ms on EU and 110 on NA(chicago). You just described what it is to play on 4ms and 110ms. High ping has its advantages as disadvantages. We all know there is a serious peak advantage in this game (thats why you should repeak widow jumping at an unexpected timing). Whoever peaks first around the corner, is often the player that gets the kill on the camping player.
With 110ms, it is easier for me to use it. Because there is slightly more delay and you have slightly more time to aim+shoot. I do better with widow on NA than on EU.
Now the disadvantage is, your escape. Every action you take to get away or counter (dash/deflect/recall/grapple/teleport/ults etc), should be done slightly earlier than what you are used to with low ping. Because otherwise you will simply be too late. You will feel like you pressed it at the exact right time (coz thats what you see on your screen) but the server disagrees. The server just gives you the finger, registers your input later due to ping delay and believes you were just too slow. Same goes for running away. Your screen tells you that you were passed the wall by a good few meters, but due to the delay, you are actually not passed the wall.
So like everything else in life, this has pros and cons. Any higher than 150-170ms btw I would say is unplayable. Game gets just too weird to play it properly.
Personally I prefer 4ms over 110ms. Even though the peak advantage helps me a lot, but the frustration of being too late with the deflect/flashbang/recall/teleport etc is just too great. Really pisses me off knowing I would have stunned the genji, but it didnt happen coz of the delay.
But coming back to you with your 20ms. Thats way too little to notice it. Maybe a little tiny bit, but it shouldnt be a game changer for you. Just relax and focus on your game. These things wonder through many minds, sucking energy, that could have been spent on focusing on your aim/positioning/awareness. This game requires so much concentration, that you cant have this bullshit playing mind games on you. You got to focus man. 20ms is too little mate, dont let it get to you. When you lose matches, analyze your play on why the game was lost. See what you can improve for the next time.
That will help you more than 20ms lower ping