Bills I cant handle

I am 20 years old and my main issue is that I have to pay $600 a month for a car that I never wanted and that I cant handle but I have a one week deadline left because I cant seem to get or hold a job because of some medical issues of mine but my point is that I am frantic and stressed and cant seem to find a way out of this besides trying my luck with Ebegging. I don't enjoy having to try this because of my pride but I don't have time to consider all of that when I have one week to make this money up or else I am forever in debt to people I cant pay and I will also ruin mine and my girlfriends credit (she co-signed). I am utterly fucked in every way and backed into a corner and just need help and I don't know where else to go but here so if you can please do help me.