i was in pvp i had All i repeat All my shields up,Cover Screen ,entrenched ,Ballistic Shield ,Shield Probe , and the did 95% damage to me in one hit and knocked me back several feet stuned.
Next time use evasion too. Then you'll be invincible.
If we had a true combat log that shows damage incoming, you'd know what hit you. Then you could post the screenshot. I find shield probe absorbs a few hits, I'm guessing you were focus fired by multiple people. Get off the train tracks.