Help me (new job problem)?

I accepted a job offer of $10.50 working as a housekeeping dispatcher in a hotel. I'm soooo disappointed. I expected this position to pay at least $15-18 an hour especially for a high end hotel in long island. I took it out of desperation cause there's no jobs out there. I have a B.A in media communication and public relations and i can't find a job in that field. we spoke yesterday and i'm suppose to come in for monday. the thing is i forgot to tell them about not being able to come in tues morning cause i have to appear in court for unemployment appeal. would that make me look bad? how do I go about asking them? and also in regards to the money...is it too late to negotiate a better amount since i already have accepted their offer? I feel sooooo stress out and ashamed of my salary what have my life come to. i really could use some advice.