Spinal Fusion (ALIF) Tomorrow 19F

Has anyone had this done? They'll be going in through my stomach to fix two levels, then a week later they'll be going in through my back to add more screws. I'll be in the hospital a minimum of 2 night and 3 days. I have already had a laminectomy. I'm terrified. I'm only 19 and I'm about to have my second and third back surgery. How bad was your pain the first few days? What should I get to make things more comfortable? What should I look out for?