Are you filing your nails following the curve of the nail or filing them straight?

Like you, I use a diamond file but, unlike you, I haven't cut my nails in years. The file does the entire job quite nicely. My right (pick) hand has rounded nails common to most manicures. But the left (fret) hand nails are perfectly straight across except at the corners where the straight filing leaves a bit of a point/spur. I round those off.

Additionally, the nails are filed short, ie., below the tip of the fingers. The fleshy tip/callus is above the level of the nail. I file fret hand nails three or four times a week to maintain that extra short condition.

The result is that where the fingers meet the fretboard the nails are straight and flat and they don't 'get in the way' .

Goes this help?

Good luck, have fun.

john