Have I made the right choice?

I had a simulation today at school...first of all, I was up very late into the night working on one of the many projects they assign, I was tired, moody and stressed.  Needless to say I did not have the best attitude going into this and I never take these things seriously because I feel they waste so much of time anyway so how can this be any better? My situation involved a woman with preeclampsia and she had come to the Dr. complaining of headache..blah blah. Had to give her medication and send her to the hospital. My issue is that right now I am so distracted with Steve needing a job, having to work night shift on the weekend, trying to figure out who is going to watch Maggie for me, (what are the side effects of Mag Sulfate and how fast do you give it IV push), how are we going to get the car fixed, (what was the doctors name and the patients), how am I going to get all my assignments done, when am I going to study for all these tests, (why is the teacher being a smart ass), these people have no clue that I am losing it and about to walk out, (I need to be medicated, better call the real dr), how am I going to sleep all day tomorrow when sis is having a birthday party for her daughter (that she expects me to come to)..these are just a sampling of what was running through my minds the entire day. What is frustrating is that I cannot tell them this, they do not care..I understand that..I signed up for this. My question after this experience today was...do I really want to do this and have I made a mistake? I am really angry and bitter right now and that is coming across loud and clear to everyone, esp people at school. I always thought I wanted to be a nurse, but now that I am almost there I am beginning to question myself and my abilities. This is nothing new...I seem to bitch and moan a lot on this blog..perhaps I should change things up..hey a girl's gotta have dreams right!