Heat / Light Stress or something else?

[MikeS17]

So far have had problems with snapping one plant and crickets eating at both of them ... and now this
Hopefully just from too much light so I've moved light (600W LED) to about 60cm from plant.
Could this be anything else?
My leaves are curling downwards (see pics) but apparently light and heat stress makes them curl up instead?
Any opinions or thoughts would be great

 

[db3]

Too much nitrogen makes leaves claw like that. Judging by the color, that’s most likely your problem.

 

[the green bandit]

back off the N a little bit buddy and she should come good

 

[MikeS17]

Too much nitrogen makes leaves claw like that. Judging by the color, that’s most likely your problem.

back off the N a little bit buddy and she should come good

Thanks a lot guys!