It's not your TV set - it's your aerial!
Freeview TV channels are transmitted in 'bundles' (called 'multiplexes'), with each bundle on a different frequency. Theoretically you need a different aerial for each of those frequencies because, ideally, the lengths of the elements in your aerial need to be correct in order to 'resonate' with the relevant frequency. Obviously that's not possible, so any aerial is only a 'rough match' to the required frequencies, with some multiplexes being easier to receive than others.
Your aerial used to be able to produce a strong enough signal for your Toshiba set to 'pull in' all of the multiplexes but now it's only working well enough for the set to handle the stronger multiplexes (which is why you've 'lost' all of the channels on the weaker multiplexes). Your Bush set has better 'sensitivity' (i.e. its ability to handle weak signals), so the problem doesn't show up with that set.
So it seems likely that your aerial has been knocked out of alignment by the recent strong winds, reducing the signal strength received by your TV. (Alternatively the signal strength could have been reduced by something as simple as vegetation growing in front of it).
So you need to examine your aerial (and the associated cabling) to see if you can work out where the fault lies. Alternatively, since the signal strength is obviously only just below that which your Toshiba set needs, a simple signal booster (for a tenner from any of the big supermarkets) will almost certainly fix the problem - although you will probably need to do a retune after installing it.