Topping gone bad

[blue.velvet]

i have a NL/WW growing in a 10 inch pot, which is 6 weeks old (from seedling) I have been Lst'ing it since it was around 7 inches it is now 8 or 9. My problem is i think i topped to much off of the plant. I cut it right on the stem, instead of the leaves too. Check this pic in between the Y where there is a little bump on top, where i messed the toppng up.

(pics not working now) but will post soon

then this is a Master shot of it

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This is my first grow and i am afraid i killed my soon to be mother. Maybe if i topped the branch below it the correct way it can still keep on growing?
another question i had was how long will it be till that plant is root bound? its been transplanted twice and i dont want to add anymore stress, but dont want it to wilt from being root bound.
last question would a 150 watt incandescent growlight bought at (plant shop) be enough light till flowering? it is about 6 inches away with a little fan and shows no signs of burning.
any and all responses are greatly appreciated.

[SmknVTEC]

No matter how much or how you top a plant it will most likely survive if there are some leaves and shoots left on the plant. No don't use incandesent lights, they don't grow anything.