See the edge of the leave, is turned up, and intending to curl with time it will
This suggests the air is too dry, add a pot of water
2-3 pints is good, and sit it along side the plant
the leaves show an excess of nutes
I'd be potting up, however you have done
considerable diy shit on that pot suggesting you like it
so cut your nutes flush with 3 times the pot volume
with air temperate/ ph ed water allow a dim light or overnite to drain
also FFOF likes a lot of perlite add 20-30%
no further nutes until you see a positive recovery
but I'd pot up
good luck