What should I do about this?

[staystrongholdurheadhigh]

I'm in high school, and in an elective I have, we have to present a video presentation on a favorite television series of ours and describe it in detail. I know about I Love Lucy the most and could talk about it for hours, but we have to have a partner for this.
My best friend is also in the class with me, but she's been absent from school for 3 days, and I hate working alone on things. I haven't gotten in contact with her on why she's been out of school so much.... but she's also in my gym class and she's out on medical leave in that class too until October 1.
That elective and gym are the classes where I frequently have to have a partner; and I hated working alone yesterday in the elective. Everyone else has a partner (groups of 2, and I'm the only one alone) and I don't.
Today, to solve that problem, I skipped school and am staying home. I've done it last year too, but today's only my very first time this year skipping.
Of course skipping IS for dire circumstances--being absent--but I just didn't wanna be the only one by myself without my friend. And I don't even know when she's coming back to school either... I could (for the elective) work on the presentation alone BUT the paper we were handed about it says we must have one for the project.
And I didn't wanna have to go to my teacher and say I'm alone, because I figure he'd say I'm a junior now and I should be able to find partners on my own.

The worst thing about it is... when we were in gym my friend told me "Don't be absent from school and leave me here by myself" since me and her were gym friends... she's the only girl I know who will be my partner in anything. Even in this case, I was here in school, and I was bound to stick to our promise, and she leaves ME hanging... I wonder if she even knows how it makes me feel. I feel sorry for her, because she has problems with her legs and/or knees (I can't remember which body part she said it was) but she said that's why she's on medical leave for gym.

She's had days where she'd be absent one day and then login to her Facebook after school was over. It always confused me.... but she's the type that will take someone for granted. Say she'll be at XYZ one day, and then when the day happens, the person's there waiting for her for hours, only to have her never show up or arrive late.

I wonder if she's in school right now and I'm leaving her hanging.... If that's the case, I'm sorry I left her alone like that as well, but she needs to realize how I feel when I have to be by myself.

So... what could I possibly do about this?

[Sheuly]

You will try your best.