Netgear Nighthawk issues - am i overloading it?

Hey all, i'll try to keep this brief. I've recently moved in to a new house & have been in the process of smartify-ing it. We're running everything off a Netgear Nighthawk & no matter what i do, the connect never stays solid. We've got: Hue bridge (Ethernet) 7 Sonos Speakers (split across our tv & dining room) 4 or 5 Nest Hubs 2 Chrome Casts 2 playstations (Ethernet - via a network switch) 2 laptops 2 Pcs (1 on ethernet) 2 ipads 2 phones Several times a day *something* drops, however it's usually not the same thing. Right now one of my Nest hubs is working fine whilst another says it can't find the wifi & i'm going crazy. I've tried a single SSID that combined both 5ghz & 2.4hgz & splitting them. I've turned off WMM & QoS. I'm not sure if it could be a issue of conflicting IP/Mac Address? Or if it's just a case of having too much on the internet. I'm very out of my depth when it comes to this stuff & really have no idea where to start? If anyone is able to assist I'd be much appreciative. Thanks all.