I'm very constipated. Went to DR. And he told me to take laxatives. I took two maximum strength laxatives and still can't poop...what could be wrong?

Your diet. The problem is your diet, life long of junk food will not be treated by a couple of laxatives. You need a lot of hydration 8-10 bottle of water, and natural juices, you need to avoid sodas, and energy drinks. You need to eat fruits and vegetables, and a lots of fibers. For now take four tablets of dulcolax, then mix half bottle of miralax (polyethylene glycol) in 64 oz of Gaterade, and drink it, repeat it once if needed.