I've not seen you flying, so I'm taking pot luck here, but I'm guessing that this....
The soul destroying part is that I was doing circuits last August, but with my 2 instructors leaving (who had taught me from day one), planes uncircuitable and british weather has meant that I have had inconsistent flying (literally around 4 flights between Oct and March) despite regular booking!
Is the core of your problem.
During your early days, you MUST have regular flights and consistent instruction. Different instructors have different styles and methods of doing their job.... add into that gaps in your flying routine and you're just going to start loosing what you've worked hard to build up.
Landings are tricky to master but easy once you've "got it" .... but the inconsistency in your instruction isn't helping matters.
Either change school to somewhere a bit busier and less prone to changes, or if you like your place, or change is not an option talk to the school and perhaps get them to assign you someone more senior who's part of the furniture and therefore not likely to up sticks any time soon.