This is how the first p-tex candle fixing job looks like for most people. Don't worry and don't give up. It's good practice to practice on small scratches, before you take your take on deep scratches.
I would say there was still too much yellow flame in your process, which results in higher temperature and carbon contamination.
Higher melting temperature results in material being brittle and high development of cracks due to higher material shrinkage. Contamination makes everything even worse.
If you do it right the material should have same characteristics as the candle before burning (transparent, elastic,...).
I do not have other suggestion than keep practicing. Try with different distance from the base, different angle, rotation and application speeds,... Once your flame burns only in blue, you should notice a difference in material characteristics.
Core-deep scratches and scratches next to metal edge are hard to do. They should be done in multiple steps in small quantities, letting it cool in between.
You get a very bad shrink on/with materials other than p-tex, so you might have to repeat the first layer on core until perfectly sealed, otherwise it is a real possibility the fix would get worse and worse along you go.
It if easier to fix fresh scratches (sharp edges) than old, rounded ones, and not all at once, otherwise it's a pain when scraping.
It is also obvious you overheated a spot on the base, which delaminated (whitish spot).
Old opened candles are bad and should be dehumidified before use otherwise they just liquify when burning and the fix is totally brittle when cooled.