Why can't I find a job?

I'm a foreign student in the US and have just graduated. I got my OPT card 2 weeks ago and I passed the boards last week. But I've been having a really hard time finding a job. It's not even as if I want a high-demand specialty like ICU or L&D - I'm just applying to plain old med/surg or general medical floors.

I got two job offers last week and when I called the first place to ask about GC sponsoring, the lady at HR flat out stated that they didn't do that and haven't done it for 3 years! She kept talking about how complicated the process is and everything while I kept trying to explain how my lawyer and I would do almost all the work. Anyway, she wasn't buying it, shut me down and pretty much rescinded the offer. Now I'm scared to call the other place. I've tried calling up other hospitals (in the north-east States and Florida mostly) to find out if they actually petition before applying and all I've been hearing is "no".

If any of you is in a similar position or have any advice or pointers for me, please share. For example, are some hospitals more willing to hire foreign nurses than others? Which ones? Keep in mind, my only clinical experience is from nursing school. At this point, I don't care which state I practice in - I just want to start working before I forget everything I was taught in Nursing school!

Thanks for the responses. I knew about retrogression but I figured I would have OPT for one year and would (hopefully) be able to ride it out. I didn't think I would have such a hard time finding a hospital to employ me with OPT. Maybe I haven't cast my net wide enough? I went to nursing school in Pennsylvania so, I got my license for PA and mostly narrowed my search to PA and NJ.

I've been following these boards so I understand petitioning versus sponsoring. I don't think the people at the hospitals I've been talking to do though. I'm going to call the other hospital tomorrow morning and try to see if I can talk to their HR person face to face. I think I'll have a better chance if I can show her how little involvement I'll need from the hospital when/if the time comes.

You don't know unless you try right?