I would try and avoid negative self talk (weak) as it can really just reenforce guilt/shame. The classic example I learned in therapy was should statements. When you think/say I should have... It can bring alot of negativity but it's usually easy to change it to a could or would statement. I would have or could have xyz. Would/could can be a slippery slope to excuse/procrastinate things but it's okay to legitimately give your self a break when the circumstances warrant it. Brains need downtime, you don't have to be filling 100% of your day
doing prep work isn't cheapening your willpower as long as your consistent and apply it to everything and not just the easy things. Another trick I learned is to try and break a task down into the smallest step you can do to make progress. Step one could literally be get a pad of paper, or change into work out clothes. It makes taking the next step easier and also is kinda like "Well I already have the pen and paper I might as well get writing" or "I'm changed so I might as well do something" even if it's just a walk or jog. But again the key is consistentcy.
Yeah that's basically the concept/book Eat that Frog. Basically if you Eat a Frog or do you least liked task first thing in the morning it makes everything else easier and not so bad.
If you can see the majority of the Doritos logo, it's the edited version.