Amy
How about posting a budget? There may be areas that you can cut that you may have not thought of.
Since the vet bills are bothering yuo the most-I would pay those off first.
I would also consider
lowering your credit card interest card rates through either asking the companies for lower rates or doing a balance transfer. Also make sure you are not charging.
Then I would tackle the medical bills since you are already on a payment plan with them.
Do you have things that you can sell on ebay or craigslist to help out?