Thank you for the additional information. Cats drool for several reasons, one of which can be because they are nauseated. When nauseated, cats are not likely to eat. Now for the tricky part: IF your kitty is drooling because she is nauseated, what is causing the nausea? This list of possibilities is very long, and the chances that I might luck into naming the exact cause are slim to none. Nevertheless, your kitty could have been exposed to or gotten into something while outside, or she could have any number of illnesses that are responsible. This current problem may be completely unrelated to the abscess, but I asked about the last time you treated her with peroxide because it is known to cause nausea and vomiting if ingested.
More frustrating than my inability to tell you what is wrong with your kitty is the fact that you cannot do anything to help her at home. She does need to see a vet, and it should be soon. Given the time, regular vets are indeed closed. However, there should be an animal emergency clinic (hopefully) nearby. It's important to remember that cats instinctually hide illness. You are seeing very obvious signs, and that can mean your kitty has been feeling a little off for longer than you think. The longer she goes without medical attention, the more difficult and expensive it will be to get her well again because symptoms compound the longer they are unmanaged. Cats are pretty sensitive, particularly when they feel so poorly that they cannot or will not eat. They are susceptible to complications involving their liver if they are not taking in enough calories. Force feeding a nauseated kitty is not a good idea, so you definitely need help from a vet.
I understand that finances are tight, but she really does need to be seen. Depending on your situation, you might qualify for care credit, which is a low interest credit card that can be used towards veterinary care. You can apply on line at the website below.
If that is not an option and you cannot have her seen by an emergency vet, pick up all food and water, and contact your local humane society or SPCA tomorrow and inquire about low cost animal hospitals in your area.
I hope she feels better soon and that nothing too serious is going on with her.....