Any words of advice?

I've been working for about a month. I just passed my boards and got my first 3 patients 2 days later. I wasn't on my own but my preceptor isn't that great. She actually sat there and read a book for most of the night. I got so far behind and all she could say was you should already have that done or you should do this first. I just wanted to scream. What really got be behind was that at the beginning of our shift she actually made me do one of her discharges after I told her I had done many of them in the past month and was comfortable with them. Doing her work actually put me an hour and half behind. I get that we have to work as a team but doing someone else's work is not team work. haven't even been on the job that long but am beginning to think I'm going to be a crappy nurse. I only had 3 patients how in the world am I going to handle 7? I know it's just the first month but I'm already discouraged. I just keep telling myself it just takes time but what if I never catch on.