Am i doing something wrong?

Ive killed the riven twins and started the main quest in sacrament that comes after that, and all enemies are just destroying me in mostly 1 hit and sometimes 2 am i missing something that will make these enemies hit less hard or i will get more damage reduction ? i have invested 20 pts in health even. This isnt challenging, its just stupid and im just wonderin is it me or is the balance of the game just potato at this point ?