i have a 5 year old persian cat HELP!?

  He is spoiled rotten, and he was the only cat for 5 years we have had other animals too. Our dog died last year and we also have a bunny, a bird, and fish a few days ago we fell in love with this 6 month old persian kitten and we bought him ... our 5 year old persian cat is not liking the situation to well .. we have our kitten in a room with a gate and our older persian always hisses and growls at him when he sees him I have also noticed that our older cat is not his normal self lately not as playful or cuddly but he isn't mean to me or any of the other house hold members .... is there something wrong? I have been giving my older cat the same amount of attention before if not more attention. should we get rid of the new kitten? I just want my old cat back I don't want him to be upset about the new addition and always be this way, but I also don 't want the stress to be put on the kitten for giving him back.
just give him time, oh, and fix them both. cats usually get angry at a new pet but then get used to him and live in harmony, might even become friends. give it time, a lot of time. might take a while. pets question and answers,www.5d2d.com

introduce them to each other slowly. feed both of them cats candy during the introduction so they associate each other's company with something nice.

how about you wait for the older cat to sleep and then bring the kitten and have him lay near him? he can't get hostile if he's sleeping, can he, and cats catch up on things while they sleep. he'd get used to the kitten's presence in his sleep. try that.
This is normal when introducing a new kitten to the house. Keep them physically separated but able to interact, as you have been doing, for another week or two until things settle down between them. After that, you can start letting them in the same room for visits, until finally they both have run of the house. The two may or may not eventually become friends, but at the very least they will learn to live with each other.