1995 Ford Escort Knocking

I was driving my car last night when I noticed a quiet subtle knocking, I kept driving it, making a mental note to check the oil when it had cooled. Later on, I was driving when the engine was knocking loudly and when I would push in on the clutch and brake to stop, it would turn off and all my oil and check engine light would come on. I added 2 quarts of oil this morning, and it only died once as opposed to the three or four times last night. I have no clue what could be wrong.