Help!! Something is wrong with my cat!?

Alright, I have two 9 month old male cats who are ALWAYS fighting. I'm saving to get them fixed and was planning to do so this next week. ANYWAYS, Marley has a lump on the base of his tail, and I figure it may be from my other cat. I noticed it when I got home from work this morning, and while I was back at work my mom said it had been draining a little. Marley has fur balls quite often, but he just came up to me and meowed two deep meows then went and threw up, and I don't think it was a hair ball. It was hairball colored but it wasn't as thick, and it had a couple pieces of grass in it, like he had been eating grass. HELP! I can't get to a vet until tomorrow and I can't afford an emergency vet. WHAT IS GOING ON?????