Missed my bus and overslept, now I can't find a ride what should I do?

My school starts at 7:40, and my bus comes at 7 o'clock sharp and it's 9:16 right now, but my mom had to leave for work very early this morning (I think it was 5 o'clock or something) and she woke me up but I went back to sleep! :C My alarms went off but I didn't hear them and slept right through!! Missing school is definably not an option for me righ tnow because I've missed waaaay too much school this year AND I already stayed home a day this week... I have finals today too! Not only is she gonna be PO'ed at me, but I'm really mad myself I really don't want to get in trouble :( I also checked, and all of my neighbors left for work already, and I know my school can't send anyone to pick me up because a few weeks ago this happened to my friend and she called but they said there was nothing they could do :/ I'm sorry for typing so much, but I really need to figure out something! My sister is the only one home with me, she can drive but she doesn't have a car... also I'm sorry if this is the wring categoriey, but I wasn't sure were to put it. I put it here because I have two questions, what should I do if I can't find a ride and how can I make my mom not mad at me?? :(