^^^ Oops!
It's seems that the 'clearance' programme affecting many Freeview transmitters this year doesn't involve Emley Moor, so there shouldn't be any need to retune tomorrow in your area.
In which case, if you're losing certain channels, it seems likely that your aerial isn't particularly good at receiving signals from the COM7 multiplex (which has channels 107 and 108 allocated to it).
It's probably fine when the signal strength is good but when it's less so (due to things such as the 11-year sunspot cycle, individual flares on the surface of the sun, atmospheric pressure, precipitation, seasonal changes in the height of the ionosphere, interference from other devices, etc) when the signal isn't as good.
If so, simply fitting a signal booster should solve your problem. Major supermarkets sell them for around a tenner (but remember that you'll probably need to buy a fly lead, to go between the booster and your TV set) separately.