Excuse me, I think you've cloned my ds2!
I could actually have written your OP and second post. My ds2 is exactly the same, has gone through the same phases, including the 2 hour wake up in the early hours, refusing a bottle and not napping in the day. He's now 11mo and has slept through 6 times in his entire life. If he wakes up once I count that as sleeping through now.
It's horrific.
It does get better, for a while, but I have found that it's actually easier to accept that he is just a terrible sleeper, rather than spend every night getting more and more stressed that he wasn't sleeping again.
I also decided that I was going ignore all the advice telling me that he didn't need a night feed. My DH works away so I had the choice of dealing with 3 dcs on no sleep or feeding ds2 when he woke and getting some sleep. A 10 minute feed in the early hours or 2 hours pacing round the room wasn't much of a contest to me.
TBH, your baby is only 8mo. He's still really small and he's going through lots of things that will affect his sleep. It sounds, from what you've said, that he does actually need the feed, or at least the comfort and in your situation, you really need to go for the short term solution and just let him bf, until you are sure he's 100% better, his appetite is totally back to normal and he isn't in pain from his teeth. Then you can start some kind of sleep training if you feel the need.
(FWIW, we did a very mild, much gentler version of CC a couple of months back which helped a lot, but in the past month he has cut 6 teeth and has a stinking cold so we are back to multiple wake ups again. The sleep training only works to a point if they are rubbish sleepers and it doesn't take much to knock them off course, sleep wise).
That's not really what you want to hear right now, is it?
If I were you (or your DW, rather) I'd feed him immediately when he wakes and see if that settles him without the 2 hours of screaming. Surely that has to be better than what you're doing at the moment?
Good luck!