Hello ! Whoa ! Nice run ! I'll try to help you at my best, my english is not quite good. I can provide pictures for expanded advices.
Just to say : you made a huge part of the game, the two larvae who left are on you path.
I'm so glad to see people like you going so far into the game despite its unatural design at some point !
For the larvae puzzle, focuse on the advices hidden in the descriptions of the objects that you collect in the differents area. You can see the descriptions in dedicated rooms. Maybe you will need a paper and pen to keep notes, or taking screenshots.
For the workshop, there is two options : If you recovered Felung (the blacksmith), her workshop is in the Abysses of Baedd, in the blue area under the herbalist's room (the one who gives you the herb box, you have to jump using the amrlet of Baedd in the pit area).
If it's Cynamaw (the weaver), her workshop is accessible by two ways : in the necropolis (the first area you explore), under the room of the guide (first PNJ that you met), there is a closed door. If I remeber well the door open if you have the good ghost BUT there is an other way : in the entrance of the mine, juste before the area where you found the larvae R, you can go at the very left and use the armlet of Baedd to jump into a secret room. Then, use the armlet of Llwyn at left to pass trough a fox-hole and find the workshop.
Just in case : did you find any bugs during your play ? I'm focusing on some critical bugs that appeared randomly (not in the app, but with the same rom), so any help could be ... helpful !