Is demerol and phenergan given through IV safe?

I went to the ER earlier today (well really yesterday) at around 1pm. for a bad gallbladder attack (which I see a surgeon about on friday). The attack was so very painful and I was throwing up too much (3 times nothing but yellow bile), and my back was so painful was the main thing. COuld not get comforable from sitting, standing, laying down or anything. So after I was processed in and talked to the ER docotr, we decided that I would get an IV of Demerol for pain, Phenergan for the nausea, mixed with fluids (basically sterile water) as a slow drip. The nurse put the needle in my vein in my arm, and started the drip slowly, as I told her that I am very iffy about pain meds and didn't really like to feel out of it and spacey. Either way within 5 minutes or so, I was already feeling it, very fuzzy feeling, and started going in and out of sleep (which was kinda good because I hadn't slept all the night before). But what time I was awake, everytime my eyes would close, it was like I was hallucinating or something, and when my eyes were open I would try to read something on the board on the wall and the words were shakey so I couldn't read. The drip lasted about an hour and after that was asked if I'm ready to go home. Of course I said yes. The whole experience was really weird, and a little frightening because I do not like that feeling, but it sure relieved the back pain and nausea so that was good. I could still feel my gallbldder contracting though but not very painful. My hubby drove me home, and I went to sleep from around 4 all the way until almost 9:30, wow was good sleep! Anyways, I just wander if that combo is ok, will I have any problems from it (I still feel kinda fuzzy) and unfortunately I am starting to feel another milder attack come on (just basically back pain and a little gallbladder contracting) but I do not want to go back to the ER, and have that very strange tail again! I didn't like it, even though it helped, the way it makes me feel. How long is this feeling going last, and has that stuff worked out of my bloodstream yet?, am I going to die in my sleep, lol, I know weird for me to ask, but after reading a little about those combinations I'm a little scared. Has anyone else had this, and did you make out ok afterwards? This was done sometime around 2:00 and 3pm, so I'm just wandering. Thank you so much for reading this long post, and if you can help I appreciate it!