My 5 yr old cat (Baby) has a swollen lymph node on his neck!?

Two of my four cats have cat acne. One of them has a swollen lymph node on the right side of his neck. It is elongated and about the size of a quarter. I know that the most common cause of cat acne is bacteria in plastic water bowls, but they drink out of our bathtub water faucet, so I really don't think that is the cause. Baby's acne has recently turned from blackheads to pimple-like sores, and I have been getting all of the puss out and putting Neosporin on it. The lymph node on the other side is about the size of a pea. He is eating and acting normal, so could it be an infection? Is there anything at the feed store that I can get him (antibiotics) that would clear it up if it is? He stresses horribly when he goes to the vet, and my vet bill is pretty high right now from recent vaccinations (on 7 animals) so I would like to try and clear it up by myself before I take him back to the vet. Any help would be appreciated!