He is very, very hormonal and going by the severity of the biting is most likely in constant pain, from swollen gonads. I don't recall if we explained exactly what happens to cause all of this distress, so I will give it a shot, it won't make it any better, but it may help your peace of mind through understanding.
A birds sexual organs ( gonads) are all inside of the birds body ( which I am sure that you already know) where they have only a very limited amount of space. Normally they are quite small and are at rest, but when the bird hits puberty and its first breeding season the combination of the length of the days and an abundance of protein rich food causes the biological clock to signal the endocrine system to start producing the sex hormones which cause the gonads to swell up and begin functioning. This is not normally a problem and in a few months the endocrine system stops producing the hormones and the bird goes through molt and the gonads shrink to their normal tiny size and are again at rest.
But, we changed everything when we took these birds from the wild and started feeding them protein rich foods all the time and we replace their normal source of light with artificial lighting and we tricked their body into believing that it is always breeding season as a result of this human lifestyle once the bird goes into puberty and its first breeding cycle their body never shuts the hormones off and the gonads keep growing. Believe it or not they are capable of enlarging in excess of 100 times their normal size and there is not that much room inside of the birds body and once the gonads reach a certain size there is no more room for this growth. This results in the gonads being squeezed from all sides and the resulting pressure also crowds and shifts the position of the birds other internal organs and this is all very painful and as the gonads keep growing the pain keeps increasing. The bird tries frantically to find some release from this, but until we reduce the protein and fat content of their food and get them on a strict solar light schedule like the wild birds are on this situation only gets worse. Reversing this takes time, a lot of time but it is the only known cure for this condition and the only release from this intense pain.
This is the cause of all of the biting and scurrying about and looking for a nest site as well as the screaming. I truly wish that there was another faster way to correct this problem for the birds sake as well as for yours. Unfortunately, there is no other effective way to treat this condition.
I see no valid reason that you should not protect yourself from him during this time as these bites are painful and each one leaves its own little scar, you don't need these things, so by all me and protect yourself until his system straightens out. I went through this with my Senegal, it took the first year for things to straighten out. It was something that is done to these birds and when it is over you will have a much sweeter bird. I could not really ask for a more affectionate bird than Kiki is now that her system is functioning properly, and GCC's are known for being very affectionate birds. Try to remember that this is much, much harder of your bird than it is on you and he truly does not want this any more than you do, it is beyond his control and is not his fault.





