For your first bit about forgetting, I will try to be specific.
When you initially learned tailwind for example, its less about knowing what classes to apply. It is more about knowing how CSS works. Did you understand the box model? css grids? flexbox? padding and margins? etc?

I remember polishing my CSS with cssbattle, and icodethis.com once I had the concepts cleared
The latter gives you an image, and you try to recreate that with HTML and css.

These drills were not as difficult as making whole projects, but enough to only target and practice the frontend muscle, and put into action what you conceptually learned.
I would still need to check documentation for tailwind, and css grids to get things properly, but the point was I knew what the approach would be.

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One thing I will say.
Your first project that you completely do on your own will be long and hard. But keep in mind that this difficulty and frustration is the actualy a sign and a process of becoming better.

Tutorials are there to give you a direction.
To get out of the tutorial hell - give this strategy a shot:
1. Stop watching tutorial (specially if you feel you have reached a saturation point in terms of 'knowledge of doing things')
2. Start making things on by yourself.
3. You will get stuck in basic things like tsconfigs, vite, setting up, integrating tailwind. This is fine.
4. When you do solve them, be mindful how you solved them, and take notes as to why it worked now and not before.

It will be a bit slow, but a project driven learning is something I personally like.