Getting back to basics to sort out range/interference issues.

First thing is we need to find out if there's interference in the area you fly in that's causing your range issues.

So , power up the goggles and nothing else ...with the Rx in the goggles on , you need to see if there is a clean static image in the goggles.
If you see lines or anything else in them , try another channel till you find one with a clean static and no interference.
Once you find one ,then change the TX to the same channel.
Next you need to do a range check with just the TX powered , NOTHING else on the aircraft/multi-rotor powered if possible (use a separate battery if you have too) ... get a friend to go for a walk out to where you would normally have your range issues.
If that works ok , then power the quad up , but don't spin up the motor/rotors yet , do the same range tests and see what you get compared to the first test without anything on.
If its worse , then you have a something noisy on your craft.
If its good , then power up the aircraft/multi-rotor , spin up the

motors and test again... if bad , its again something noisy on your aircraft/multi-rotor causing it.
Then you need to narrow it down to find out what it is.

All that said , have you tried a different area to fly in , just in case your normal area is noisy as !!
Just use a process of elimination to work out where you issue is coming from.

Antenna placement makes a big difference , you want it a clean line of site orientation as things like carbon-fibre,batteries,other equipment , and your frame itself can block your signal.

Also remember that all antennas have a NULL( usually straight out the top )where there is little signal emitted or received , so you don't want the NULL pointed at you , or the TX.