You are frustrating your bird. Being pet is sexually stimulating for your bird. Unless you are able to become its mate, only scratch/pet your bird on its head, and neck.
Back, belly and wings need to be left for its mate.
I just got a parrot, at first he liked being petted around and being talked to and whistled to, but a day later he turns all aggressive and mean towards us, we buy him toys, bite able toy, cage, give him treats, and he does not like being petted anymore.
Possible reasons are maybe that at first, we gave him some Grapes, Blueberries, Watermelon, etc. the first day, than the second we bought him some real pet food, the one that has just one little cracker combined with many fruit flavors, maybe he didn't like that.
Another is that my turtles are at the side of him and maybe he's a little jealous.
Another might be that he might be bored from having all the center attention, I know not to ignore him because he will become more independent, maybe its because of age?
Also, if my bird moves his head while making noise, does that mean he's excited?
And if he moves his head in awkward positions tilting, is he confused?
And what do I do if he is aggressive? (I can tell because his feathers go up and he looks ready to strike)
Also, if it helps my Parrot is a Dusky Headed Conure, he is dark on his head and going to below his back the feather color turns green, the bottom of his tail is Blue & Red. The age is unknown. He does not look old though, he sounds like a young bird.