ADC positioning

I'm an adc/mid lane main and i find that in silver its hard to stay alive in fights as adc, not so much mid because they have more cc. I do think i position fairly well as an adc in teamfights but the enemy bruisers jsut run at me and kill me because people in this elo dont know how to peel so even though im positioned well behind my tanks, my tanks just run at their back line leaving me alone to die.... how do i stay alive when this happens?