Yes, it was HCM she suspected, thanks sugarcatmom. Right now there is a lot of fluid around his heart and lungs, so it's hard to tell. I know that the ultrasound will be crazy expensive, especially since she mentioned that he would have to be sent away to do it.
I'm strongly considering changing vets - the excessive charging of money isn't the only problem - she also completely ignored me when I said I thought Jake had fleas - didn't even check him out to see. She also didn't seem to have any answers when it came to his eating problems - she seemed to think that an almost 17 pound cat should be fine eating a quarter of a can of Friskies a day (which was about all he would get down over the past couple of days) - he should be having two cans a day!
Anyway, I'm asking around to see if anyone knows of a better one in the area - I want Jake to have the best care possible, and I'm very frustrated and overwhelmed right now.
He's on a diuretic for the fluids, and a heart pill called.. dang, Fankor? I know that's not it, but I'm pretty sure it ends in 'kor'. Man, I sound horrible, but I'm at work right now and his pills are at home. I guess I wouldn't win any memory games when it comes to what's wrong with my cat lately. lol I think I've just been a little too overwhelmed with the whole thing.
Thanks for the links, sugarcatmom, I'll definitely give them a read, and give you some more updates when I get them.