Any Vets out there...please help me!?

I have a older cat and I am not sure of her age...she is not a spring chicken I know that. The last few days she has not age or drank much. I just noticed tonight that she has a growth under her mouth and she also has a fowl order near it too...almost spells like her litter box. I noticed too she has some exposed flesh by her right front foot. I don't know what this is...could it be Cancer or is it something that might be treatable? I don't have much money for vet fees and I hate to see her suffer. I love her sooo much. She is weak and walking funny but still greets me and looks me in the eye when I talk to her...that hurts sooo much. :( Please help! Thanks!!