A large all-channel antenna like one of that size should do fine. I wouldn't recommend that you buy one of them (at this moment), but I would recommend giving the one you have an appropriate test.
Go by your local Lowe's store and see if they have one of these:
https://www.lowes.com/pd/RCA-Outdoor...former/3724168 Not all stores happen to stock it, so check online first. That particular transformer is the same cheap component that Winegard uses on the RCA-branded antennas that they manufacture for VOXX. It works well enough if you manage to install it without breaking it as the leads are VERY flimsy.
Try the new matching transformer, clean any corrosion from both the transformer matching leads as well as any connections between phasing lines, use a NEW length of coaxial cable from the antenna to your TV set that you will be using for your testing. Take that old amplifier and drop it off at a local recycling operation. If you were using the specific model you showed, that would explain a good deal of your unfortunate results as it's an FM/VHF only and is intended to specifically block UHF channels.
These suggestions are based on the specific information you provided. If that information was not correct or was otherwise faulty, then my recommendations are not based on your actual conditions and are probably incomplete. However, simply doing the maintenance on the antenna, a new transformer and a new coax takes everything to a fresh start and eliminates a lot of potential pitfalls that are yet to be discovered.