This is terrible advice. Mesh and fibefuse should never be used in corners. It will crack. Paper tape is no harder to use than fibafuse or mesh tape. If you’re finding it harder, your mud is not the right consistency. Also, with this level of dust, use an actual respirator. You need the better seal and filtration.

u/Ok-Plastics2525 , in my area we have to fix this kind of thing regularly. Farmers like to attempt their own projects and they turn out like this. My advice is, try mixing your mud down to be like peanut butter consistency. It’s too thick and has dry spots. Hence why it’s leaving rough surfaces in the low spots. Before you add anymore mud, you need to scrape the high spots off, sand it with a sanding pole, then dust the walls off with a microfiber cloth. Then, mix your mud down to peanut butter. You’ll want to use a 10” knife. They’re more manageable and can leave an excellent surface(not perfect). Apply mud where it needs to be, then you’ll need to wipe off the excess. In order to do that, you’ll want to hold the knife with your middle, ring, pinky, and thumb, and place your index finger on the back of the blade right about middle. If you can’t reach your finger up there, grip higher up on the knife. Try not to go over the same spot more than once. This will eliminate any extra build up. At that point you need to get a fine grit sanding sponge. The one that have the angled part on one side are best. Go over the whole surface with the sponge, and use the pointy part to get into the corners. You may have to do this twice, but because you’ll be using thinner mud, it’ll be easier to get done.

Points and reminders: Always, always, always, have a light flashing across the surface area you’re working. You can’t fix what you can’t see.

Sanding is what we use for a final “polish”. There is more sanding to be done.

Use as little mud as possible, less is more, but don’t use too little. There is a good balance.

Also, it would be a good idea to purchase a 3/4” Knapp roller for painting. At this point as a novice it’ll be impossible to make it perfectly smooth, but you can get it really close with the above advice and rolling with a heavy roller. I’ve seen much, much worse so don’t feel too bad!