Temps don't look bad but that light looks incredibly close to the tops. You said the light is 7" from the ceiling and 18-20" from the plant -- but that pic makes it look like it's much closer to the plant then it is the ceiling.
I'd do one of the following:
- Raise the light
- Lower the light intensity (does this light have a dimmer?)
- LST / HST the tops away from the light (only if you had more time before finish)
Since you're chopping relatively soon your options are limited. I think your best bet would be to adjust those hanging wires and find a way to get a few more inches of height there. Halving those wires would get you quite a bit more room.
I'd also suggest getting that light on some sort of ratchet system for next time. This way you can get the light as close as possible and adjust as the plant grows. I keep my QB's ~18" from the tops of my plants at all stages of flowering, adjusting sometimes daily as they stretch.