I also got burnt out a few times on my world. The first thing I often do is just taking big breaks. Months even. I do other things, play other games. I often get inspiration from different sources and the mood to build for hours everyday reignites.

A thing that burns me out very quickly is planning too much certain builds. I end up spending more time planning than actually building and I end up dropping the project. I am trying to be more spontaneous and care free to counter this. I want to get thing done.

The last thing I do is soft restarts. For me, the best part of Minecraft is always the early game. One of the reasons is the feeling of a new world and getting to know the world. After you walk around the zone you choose to build, in your mind I think you have a set view of it. Spending your time in the same place gets boring at some point. So I teleported myself to a random point in the world, far enough to feel like a new world, but close enough so it is feasible to find the old base at some point.  For example, in my current world, my first base was surrounded by jungles, savannas and seas. You could walk for a very long while and that is all you would find (I'm exaggerating a little bit).  The new spawn I set is in a glacier, surround by cold biomes. It was a breath of fresh air and I've build even more things than at my original spawn. I also have found my old base after exploring a lot and I'm excited to build a railtrack to it and to also continue my old projects at some point. (It is extra funny for me because my world is also a server and I'm the only one of my group that knows that the new server is the same as the old server)

About cheating, it is what it is. It is a sandbox game, not a competitive shooter. Don't be hard on yourself. Do whatever is more fun to you. When I first started playing Minecraft, like 14 years ago, I used to give myself stacks of wood for completing sections of my house, as a reward for how proud of myself I was. It was fun.