The Insatiable Demand For Attention

Last night my 17 year old son, B was almost totally incoherent when I tried carrying on a conversation. I had to repeat everything numerous times before he could repeat what I said, and then I'm sure he did not understand what I was saying.
He could only latch onto a word and would focus on that, never mind what was being said. I'm sure he was stoned  In fact, when I was to pick him up from basketball he told me he might be able get a ride and he would call. When he did call, he was at the gas station, which made no sense at all.
When I picked him up and asked him why he was at the station, he refused to answer. OK.
He was unable to sit still at home, and it took him 30 minutes to pour soup into a pot and warm it. He could not concentate at all. His eyes were very dilated and he continually babbled.
For the second night in a row he was up until 2 or 3 am. All the lights were left on, the TV was on and there was a mess.
At midnight last night he began knocking on my door to get the remote, which I had taken because he needed to sleep, not watch TV. He harrassed me for a very long time until I opened the door and tried to get him to go to bed. He looked like a crazed man and was physically trying to get past me to get the remote.
When I woke up I found my book, "I Hate You, Don't Leave Me" burned and left on the countertop.
I don't know what else he might have done, but I was afraid during the night and always sleep with a weapon within my grasp. I do not trust him. He is not violent, but people can do weird things when they are out of their minds.
His response this morning about all of this: Dad, you need help.