Help!

this is crack, ur plant been sniffing all day

Beginning of nutrient burn.

Maybe the early signs of magnesium deficiency either due to pH or just non available. Has any of the stem got vertical purple stripes? If so the that'll be it. Fix it with a calmag foliar

It's hard to determine at that stage. I've seen that before sort of. The version i saw was more advanced than that is though. The 2 times ive seen that before it was deemed to be pH fluctuation in the soil, but in my case it was water culture. The other was nutrient burn. The nutrient burn was more brownish though whereas the pH fluctuations were a more greyish in colour. That's all i can tell you from my end.

I think you might have been too close to the lamp, but your buds aren't standing straight up. Try giving a bit of calmag and see if it gets better. I can help with nutrients too if you're using them.