bird acting worse now then when young

I have had a green cheek for 7-8 years and lately he is really bad.Constantly squealing.He has everything he needs,not neglected at all.How do I get him to stop?
I am even thinking of getting rid of him.

Exactly what do you mean by him being "really bad"? You said he is constantly squealing. Do you mean he's being excessively loud and screeching, or just making a lot of sounds?

Assuming that your issue is screaming, I can give you one method I've heard works really well. When birds scream, they are usually giving a contact call, meaning that they want to know where you are and what you're doing. In other words, they want you to respond with a sound, so when if your bird screams, and you yell at it to stop screaming, you're actually reinforcing the screaming by responding. The method I've heard is to simply ignore the bird when it screams and give absolutely no response. This means no sounds whatsoever--you talking, a sink facet being turned on, a floor creaking, etc. Eventually, the bird will learn that nothing happens when it screams, and it does not get the response it wants, and will, therefore, stop screaming. This method does often take some time, though, so you're going to have to be patient. Hope this helps!

He was mostly always quiet.He would watch what we're doing,now its squawking at everything.People would come over and he'd be quiet,now its squawking.Can't even watch tv in the room.it's really upsetting how he is acting.

Voices, especially higher pitched voices, whether on TV or live, are very stimulating to GCCs and will cause squawking. Other household noises stimulate squawking as well, such as water running and small appliances. Maybe that's what is happening.

I'm also curious how much time your bird gets out of its cage and whether its companionship needs are truly being met. As a single bird, he needs to be out of his cage and hanging out a lot with his "flock," some of that time in physical contact. The squawk sounds like his expression of an instinctual need to connect. I keep my GCC out 90% of the time when I'm. She follows me around, is on my shoulder a lot, and also hangs out on top of her cage within eyesight of me. She rarely squawks. That might help you.