Inno keeps overestimating how much she can do within her self-imposed deadlines. She justifies it by saying the estimates push her to work harder but what it ultimately does is cause her to overstress about it all, which is terrible for one's mental health, especially when it keeps happening over a long period of time. She doesn't accept that the parameters have changed and she cannot keep treating this game as it was back in 2016.
When this project started off in 2016, she made it one of her goals to release a new update every two weeks. This was easier to achieve because there was less of an amalgamation of code to manage every time she wanted to add something. Things have changed. Her workflow, health and motivation have changed, yet she keeps ignoring the signs, either due to foolishness, stubbornness, or both. She has been taking breaks due to personal and health concerns more and more often. Progress has slowed down over the years and if it keeps up like this it may come to a halt completely.
Stress, fatigue, headaches, light-headedness - there's a plethora of conditions that cause these. However, one condition that could easily be affecting her, that includes all of these, is burnout. Resting is good but it won't solve the issue if she's going to return to her old methods and workflow right after. She needs to change her approach towards development and slow down in order to do more in the long-term. But I doubt she will. Stubborn people only learn when something drastic happens that forces their hand. Her health is going to have to implode to dangerous levels for her to realize she can't continue like this...
She's going to hit rock-bottom one day, the question is whether she will still be able to work on the game at that point (or even want to)...
Some of us may be jaded but at the end of the day we still want the game to succeed. Her subscribers could have influenced her for the better, instead, they chose to ignore the problem, either due to ignorance or because they didn't want to besmirch their reputation and hurt the developer's feelings. Even now, you speak anything that isn't outright praise and you get told off, point in case was that Sub.Star comment where one person told her to get a team because she was overworked, and got called "rude and impatient" by the community. We were the first ones to point out that Inno's workflow wasn't sustainable and would lead to problems down the road, we warned about this years ago, but since we're the "salty malcontents" nobody cared...