Should I take my cat to the vet?

Im very worried about my 7 year old cat lately. I started noticing signs today that something just wasnt right. First it was his mood. He seems very irritable, (this could be from the fact that I just got a new kitten two weeks ago, but they have been getting along fine) He doesnt want to be petted or held, which two days ago he did.. Hes very tired and when he meows it comes out really hoarse sounding. He has also been trying to throw up, and making noises like he is going to throw up but nothing comes out.. Is this a serious thing? Im very worried hes my baby, I dont want to lose him.. When should he see a vet? This last thing may seem weird, but where his whiskers are, the holes around them seem larger and more noticeable then they were a couple of days ago.. Im really worried that something serious is the matter..