Grabbing breaks
Find out what shocks you have on your car, because by the sound of it, you should replace them. Excessive brake dive is not only "unsettling" but also tends to increase brake distances as well.
BTW, I have experienced what you mention, however if you're braking too hard with this situation and you're wearing your seat belt, then I highly doubt your body will hit anything other than the seat belt.
If you're not into drag racing, then eventually you may consider replacing those with some shocks that have much better valving suited towards handling.


