To much heat, to much fertilizer, and you can also have to dry climate. And it seems like you have a calcium deficiency as well.
I think you need to stabilize ur medium with the right ph! And the right EC and try to give it a little colder climate and maybe lower the intensity on your LED if you use LED.
But main thing to do is stability in ur medium with ph and ec!!! I promise this is the solution but it may take 1/2 weeks to recover and be healthy again. But start now to flush ur the wrong ph and ec