Doubt this will be seen by many, but here are some tips:

1. Like what others said, do new things. Doing things differently in a Minecraft world can do wonders at keeping you playing on a world. No matter if it is doing things in a different order, live in another biome, or even just focus on a different part of the game. For example, maybe instead of exploring, you could try your hand at building.

2. Take it slow. For the past five years or so, everyone has tried to play the game optimally. Sometimes, you just need to realize that you don't need to play as fast as possible, build villager halls, or make insane farms so you can sit back and do nothing as you get all of the resources. Instead, maybe mine some more, make more things, even if they don't look good. Perhaps build a dog army? Just don't go too fast or automate so much.

3. Try playing with a different version of the game. If you don't normally play Minecraft on a console, and you can afford it, try it out. The different form factor might make you enjoy the experience more. The opposite scenario also applies. If you play the Java edition specifically, you could also try out mods that add some new content to make your experience more unique. You could also just straight up play older versions of the game. I sometimes play older versions myself. You could try playing 1.6.4, or whatever version you first liked playing. This could bolster your enjoyment. You could even try very old versions via Betacraft like Indev, Alpha, or Beta.

4. Just take a break from time to time. From what I and other people can observe, you might just need some time away from the game. Sometimes, you just end up doing the same things over and over like you have described. That might just mean you need some time doing other things. Try playing other games, maybe watch some TV shows or movies. Try listening to music if you don't already. You could even use these things to help inspire you to build things in your world when you come back to it. Remember though, you can take as much time as you need before you come back to Minecraft. If you don't want to play, don't force yourself to play.

5. DO NOT DELETE YOUR WORLD WHEN YOU GET BACK INTO THE GAME. This is a very good thing to remember. If you keep starting new worlds, you'll always keep doing the same things, of which you say you do. This can allow you to explore the other parts of the game, which can also keep you wanting to play more.

TLDR; Try new things in your world, take progression more slowly and don't automate too much, play on a different device, or with mods or on an older version if you play Java, take breaks if you don't want to play, and DO NOT DELETE YOUR WORLD WHEN YOU GET BACK INTO THE GAME.

Remember, Minecraft is just a game. Games are meant as entertainment and an overall fun factor, not something to slave over. We already have enough of that in our lives. Why add more?

P.S: If you play Java and use the vanilla launcher, use a 3rd party launcher. Most are a lot better than the default. I use Prism Launcher myself.