You are severely overtrained cut back on your workload and your arms will grow.
See...I don't think so.
Since I started training this way about a year ago, my arms have gained 1/4 inch. That's a lot more results for me than I've had in a long time.
I used to powerlift, so I rarely trained arms, and that, I can tell you, did not help. The lack of stimulation didn't seem to improve the shape or size of my arms...they were as small as they'd ever been, though plenty strong.
In fact, my biceps look the best they ever have, and I'm hitting them about 3x/week if you count my back workouts. But my triceps are lagging behind...maybe I need to train them more.
I honestly don't really buy into the assertion that I'm overtraining. Sorry. I work a desk job in an office...there's no way that what I do in the gym, including my day to day life, is so stressful that I can't recuperate from it. I add in 2x/week jiu jitsu practices, and honestly, I don't think I'm anywhere close to overtraining.
When I was doing three-a-days in college and lifting in the evenings during August for training camp in football...now that was close to overtraining, but I still recuperated and got stronger and faster.
Lifting weights in a gym is, relative to training camp, a joke. If I were only eating 500 calories/day, maybe. But I eat enough.