MissMarie- To answer your question "how do people cope while loved one is in rehab?" I can only speak for myself but I slept soundly for the first time in years. But I wasn't blindsided, I was deep into the throws of my daughters addiction, so the fact that she was safe was such a relief, I literally slept for days.
I was not allowed to see or speak to my daughter for the first week, she could not call anyone, other than parents (she didn't have a spouse) for a month, so I understand why you would not be on a contact list.
I know this is hard but consider backing off for a little while to allow your boyfriend and his parents to develop a plan about his recovery. You can attend Al-Anon or a gamblers program in the mean time which would help you learn about the recovery process.