After 3 days and a lot of tinkering I think I (really, we) may have solved it!
Checked over all the settings and options on the Netgear. I knew it wasnt the fibre to the house so checked a few more things.
I made the error of the century, by not having my fucking antennas on my PC. what a twat. Still though, it wasnt working fast at all still which was extremely weird.
I noticed 'Smart Connect' was on in the Netgear app on my phone and switched it off - spoke alot to @crispymorgan and @Diddums across the past few days and decided to try and split devices across whatever channels i have to offer.
Spin forward a few more hours and last night I had my PC on Wifi received approx 200mbps download and upload - managed to delete and reinstall Star Citizen within an hour whilst the guys were online.
Also had my PlayStation on a different channel, playing Destiny and downloading a game. Testing it like this seemed to be the best way forward and it's seemed to have worked great!
The only one thing that needed abit of a push was our TV in our room - I still have my Wifi booster for the channel that 'other' stuff goes on so that's in the hallway nearer to it, so that still works.
Fingers crossed it will all still hold up now - suffice to say its send my round the twist but having you guys here to tap into and help me get through it all, I'm super glad and grateful! Cheers all!