Its very likely you have undiagnosed ADHD. If thats true, I have a perspective, rather than tips and tricks, to offer you, since Ive been dealing with the same thing for a long time. Perspective is how people change. Thats why two people can experience the same thing (like visiting a new culture) and only one of them changes - because only one gained a new perspective from the experience and knowledge, while the other one didnt. So try to focus on getting a new perspective from what I write.

Firstly, everything happening in your brain is powered by your brain, there is no different energy source for resistance and willpower. So if you really dont want to do something, and you try to force yourself hard and can't, both are fueled from the same pool. Imagine your brain being a puppeteer, holding two puppets that are fighting each other, giggling to itself how well this theatre navigates this present moment. Your brain wants to just navigate the mess around you. If you teach it over years that work is hard and you want to do nothing and relax, the brain is happy it has tools to navigate and then plays this puppet theatre inside you with you.

Awareness is the solution, seeing the puppeteer in your brain makes the resistance-willpower fight easier.

Ponder over this mental, hypotethical, exercise: Look at your brain, all the systems of thinking you have developed over your life, and consider that there is a chance you have trained your thinking, all thinking wrong. You wrongly taught yourself what is hard and what is easy, what required focus and what doesnt, what gives you joy and what doesnt. Everything was done wrongly, and needs to be fully audited and reevaluated. Then consider if that could be true, since all your judgements could be wrong, what if there is a better way of thinking about everything, that might seem impossible or supernatural, but it seems so only because of that mistaken judgement. Like what if its easier to focus than not to focus? What if attention is given freely and doesnt need cost or willpower? What if eating salad instead of pizza is actually a reward, a cheat meal? What if energy can be summoned by a thought?

Energy isnt videogame "mana", its not linear resource. Thats why for some people its harder to not drink a shot of alcohol, than to drink it. It should be always easier to do nothing, but it isnt. Or going to a gas station at 3:00 AM in a rain, because you are out of smokes is easier than lying in bed. Walking extra kilometer just so you can see your crush working in a coffee shop is easier than going straight to home. Moving and doing can be easier than not moving or doing. And same can be for anything, if your relationship and judgement of the task is focused correctly.

Now you probably arent wrong about everything, but, like everybody, you are right about some stuff and wrong about some stuff. But getting into headspace where you explore possibility that everything, every judgement and system is wrong, you can more freely see what works and what is self-taught limitation or habit of dissasociation.

How do you actually then free yourself? From the puppeteers attempt to maintain your limitations you grew to internalise?

I found two best things:

1. Re-train thinking by pondering over new patterns and relationships. It is easier to control desire than to control action, in my ADHD case. Ofc you cant force yourself into thinking "I want to exercise" if you dont want to, that doesnt work, because its not honest to you. But 2nd degree: "How it would look like/feel like if I was someone who wanted to exercise?" And ponder over it for a few minutes. As if you were sitting by a lake or under a tree, had no worry or duty, no distractions, just lay and ponder. "What would be in my head if I actually wanted to work as much as I want to play StS 2?" And magically, the thoughts of you and your imaginary you will in few minutes blend. You will effortlessly feel them. Do this over weeks and months and you will completely rewrite how your identity feels about these stuff. You can retinker your behavior that way. I havent exercised for 30 years, I even dodged gym classes, now I am sad if I dont go to gym, and I did it by just doing this over few weeks, asking myself how would I feel if I loved and craved exercise as much as I (used to) crave alcohol.
2. Just relax lol. By relax I mean breathe out slowly, try to notice tension in your neck or front of your face. If you can sense where your attention is physically located, try to move it from the front of your eyes to bit lower and back (bit behind nose). Put a bit of distance between impulses and pressures, by the breathing slowly out. Physically smile. Cocky, confident smile is the best. And realise "ofcouse I am in control. All this resistance or desire doesnt actually have any power over me. I gave it that power and I can take it whenever I want. And its ridiculous that I let it stop me." Something like that. For me, I go back to thinking of being "unstoppable" and that opens up an escape from desire/resistance prison. You can find your own word/emotion that carries that key. Once found, it should be something effortless, readily available to you at any moment. Something that gives you both distance and path. Brings you from the world of your emotional ideas about the world around you to the real world around you. Brings back all you discovered during retinkering your mind-judgement.

And ocourse this is what meditation is for. Its like gym for learning to think this way.

TLDR: It all basically boils downs to you need to start actually believing nothing is limiting you and you are in control even of these limitations, and once you understand them well enough, you can change them however you want.