SCARED OF BARIUM BUT NEED TO DRINK IT - HOW SAFE IS IT?

I have a Barium Swallow test tomorrow and soon will have a CT scan. For both x-rays I need to drink a liquid contrast named barium and I AM SCARED TO DEATH! I don't want to drink this stuff, and there is so much of it. Is this safe to drink???? How safe is it? I DON'T TRUST THIS STUFF BUT I NEED TO DO THESE TESTS FOR PEACE OF MIND WHAT CAN I DO??? HELP!