Took 2 5mg laxitives to relieve constipation. instead i had cramps all night, threw up twice & pooped every 15 mins. this never happened before. why?

Two might : Be too much for you . Some people go through what you had gone through , get severe cramps / blood in the stools. You might want to try bene fibers , metamucil, MiraLAX (polyethylene glycol) etc drink plenty of fluids , increase fibers and fruits to regulate yourself . Goal is to be able to go two three times a day without straining and softer stools.