Do I still have hope of dunking?
Yes, no problem. 175cm, 85kg can touch the board, 83.2 can lose weight and dunk. However, it depends on how many years you have gained weight. If it takes a long time, it's good for you to lose some weight, because you have been exercising under a heavy body before, just like weight-bearing training, as long as you are gentle and dunk with all your heart.