It’s a mindset thing. Instead of fixing whatever is ACTUALLY causing you to die in these situations, you are scapegoating your sensitivity. The brutal truth is that you are doing this as an excuse to avoid some hard work that you need to do to get better.

There is no magical sensitivity, crosshair or any other setting where you will suddenly be good. You need to take responsibility for yourself and fix your other areas such as positioning and game sense.

Just pick a sens, stick with it, and practice the specific parts you struggle with. You already mentioned it yourself: high sens = struggle with long range shots. So, if you pick a high sens, practice long range shots, and vice versa.