Hi Jenny, my little boy Charlie is exactly 5 months old on Dec 5th and we're having problems at night in that he is waking every hour/90 minutes or so too. Oh yes its exhausting isn't it!! I'm not feeding him each time but even when I have fed him he still wakes an hour or so later. I read in the BW book that Tracy used a dummy to wean one baby off his night feeds but if you dont use a dummy that might not appeal. We've had all sorts of dummy issues anyway so thats not really an option for us.
I'm pretty much at a loose end too so sorry I can't help you much. We usually settle Charlie by shhh/patting him and that usually gets him back to sleep those times that I haven't fed him although he still wakes later

. Maybe you could try that? The only thing is he may make some noise while you're doing it but may only take a couple of nights and might help him settle himself without food. The only other thing that comes to mind is maybe changing EASY to 3/3.5 hours so that you know he's definitely getting enough calories during the daytime? I still feed DS every 3 hours although I am starting to try and stretch it out to 3.5hours in 5/10 min increments. My concern is that he might be hungry but I thought that might be more to do with my supply decreasing and I've had some great support from the girls on here so am working on that.
Big hugs to you though - I know how tiring it is getting up all night! I dread the nights now... Let me know if you get it sorted and good luck!
Michelle x