You can't unless you have higher runes, epic crafted gears or serious self heals. Church potions can help but, if you die that quick, it's not much good in your case. Better go questing in Kirah and return to finish up the Defiled Ruins instance after you get better gears and couple more levels unless you get another player to party with so that your single death doesn't wipe out everything. That instance doesn't give anything that significant that it would be a great loss, if you don't get it before over-leveling the place.