Again my mind is running rampant and won't let me move away from this. I really don't know if anything that I will say will be helpful for you given your circumstances, but nothing ventured, nothing gained.
I am first of all basically a night person, who has always preferred to sleep during the day, I am also normally a very light sleeper and in addition to that I only sleep a couple of hours at a time.
Since my preferred sleeping time is during the day, natural sunlight does not interfere with me sleeping, so if that is true for you, then moving his cage to your room while you are sleeping would place him where he can see you and may eliminate his screaming for you while you sleep and still allow him to get normal exposure to natural lighting especially the crucial twilight periods that so greatly affect their hormones and mating drive. If that will work for you it will solve many of his problems in the long run.
This would then leave it to figure out how to give him the out of cage time as well as the one on one time that he is craving. This could be broken into two time periods once before you leave for work and once before you go to bed. Sometimes more times out even for shorter periods of time can be more beneficial for the bird than a longer one time deal on a daily basis. You could still take him to your friend place like you are currently doing. All of this combined would allow your bird to live a much more bird friendly lifestyle, which is much healthier for him. It could make the use of drugs unnecessary as he would be receive an better light schedule and still allow you to get the sleep that you need as well as probably more interaction time with you as well.
Think about it, try these suggestions and see if they help you and your bird. I think that these change would be beneficial for both of you. Let me know what you think or how it goes if you try them.