Welcome! Sorry you need to be here though.
Nocturnal hits suck. In my opinion because you don't realize they are there until they jack up a good bit. As a 'nocturnal' myself, I will address that. Grab some caffeine as you head for the O2 and down it fast. Cold seems to work best. I use iced coffee or V8 Energy. The shots make me vomit. O2 will kill a hit, but not prevent the next one coming behind it. If you are getting hit every two hours at night, you will kill the first, fall asleep, get the next one on time. Your O2 will not prevent the next one. Are you hyperventilating on the O2? Do that till the pain recedes. Then stay on for another 5 minutes with a normal breathing rate and the O2 turned down to support that.
Many people think that if they get another hit in an hour or two, the O2 is not working. Well, it is. It is an abortive, not a preventative. So, the next hit is going to come!
Sleep in a recliner partially reclined but with your head above your heart. It helps a lot and you will wake sooner if you get another hit. Pile pillows around until you are comfy and secure.
Start hyperventilating when you first get up. It really helps even with just plain air. And you will use less O2 when you get there.
Eat regular if possible and schedule your sleep. Naps can bring on a hit and having screwy times to go to bed is just aggravating the dragon. Set a time to sleep and a time to get up. Stick to it. Really tough with night time hits, but very helpful.
You do not mention a preventative, are you on one? Verapamil perhaps? That is normally the best one to take and the first one you should try. It is a cheap med to take. With CH, you likely will need a pretty high dose. Likely he will start you with 240 a day and step up from there. Insist on the Short Acting vs the Extended Release- it works much better for us. And you can tailor when you take your pills based on when you get your hits. At three times a day, I took my first one at noon, then dinner, then late at bedtime. Just keep them at least 4 hours apart. Unless you have other health issues that get in the way or have low blood pressure, you will up your dose till you get relief.
If you get hit with no O2 around, then grab some caffeine while running really hot water in the tub. I get in and let it fill with water as hot as I can stand it. Often I have a full normal tub full by the time I get out. I just keep adding more hot as it cools off.
ATB and I hope this helps a bit. Hugs!!!