Very squishy tank with my WoW Deathknight. Help?

Ok so im using my lvl 70 Deathknight, blood presence, and have a good blood talent build. My gear is pretty decent. Most of it with parry and dodge bonus's. One flaw i find is that i'm just so squishy and take so much damamge that the healer cant keept up. Im talkin about like a mob of 3 too...its sad. idk whats up but help would be great.