Soulful. I didn't sleep properly for years while my soon to be ex was living with me. I too, stayed awake worrying about him, knowing that I should not worry as it was pointless. Since we separated, I sleep better. Initially it was difficult and I was crying myself to sleep every night. It gets better. I think you will feel a sense of relief once you get away, and I think staying in the AirBnB is a good idea for the time being. I hope that you get some respite from the madness soon. Things will get clearer in time. It takes a lot of time though. Also, the less sleep you get the more likely you will get sick or depressed. So please make sure you are able to sleep.
As for the 10 years together... so many people here have had 10 years or 20 with their addicts. I know that during the time I was with my husband, it was real for me, I sacrificed so much for him. I know that for most of that time, he was trying to make a relationship work because he wanted a relationship -- not necessarily with me, it was never about me, it was always about his wants, his desires. It was not really a real relationship, this is just using people. No matter what he felt about me, he used me, because the relationship was primarily about him, his addiction or illness, and he was dishonest with me. For him, this was okay. For him, this was proof that I loved him: I was "understanding" of him... yet it was not enough because what he really wanted was to drug himself, and it disappointed him that he didn't feel the same dopamine rush in our relationship that he felt when he was drugging himself.
For a person in active addiction (meaning, they have used drugs or drink or engaged in any addiction recently... in the past few months, for example), the idea of being able to engage in the work of love, the compromise, the care, the responsibility of love, is not enough. Love is never enough -- they don't have the energy or brain-space for love because those things are taken up by thinking about their addiction, thinking about how to get the drug, when to use it, where to use it... etc. They want to get high. They don't want love, really, because they have already bonded to their drug or dysfunctional behavior the way a baby bonds to its mother. I know that sounds messed up, well, it is. Your husband in particular, has more than just an addiction problem. He sounds like he has some personality issues (I hope you're not offended by me saying this). I think my stbxah also has personality issues.
You have been through so much. You felt real love for someone who repeatedly hurt you and your child by their behaviors. So the past 10 years were real... for you. Was it real for him? It's likely that nothing was real for him because he was busy being high, drunk, whatever -- he was out of his head (or coming down from something). His real life was the roller-coaster of chaos. He put you and your kid aside so that he could get back to you "later"... because he probably has a fantasy that he can also fake a "normal" life when he "one day" quits. Meanwhile you are living in the real world and waiting for him to "wake up". ALL his actions are about him faking something. Him taking drugs is him faking happiness.
You are doing the right thing by trying to leave.
He stole time from you. The lost time is something I struggle with most.