Couple things my man. Those seedlings look severely over watered to me. Especially with what you where talking about. I wait to water until it is mostly dry 2 inches down. The soil stays evenly moist throughout because of wicking unless it's over watered with a big pool in the bottom drowning your roots.
Also I used a 400w mh conversion bulb to start my grow, temps are pretty much even in my opinion. The mh will help tons with keeping your plant short and those nodes packed together. Use the mh and veg nutes until you are 2 weeks into flower and the plant will stretch a lot less. Mine literally stretched 10% - 15% and it's a sativa! Known for crazy stretch up to doubling in size!
Subbed to see the journey. I was there too not too long ago! Don't give up hope, just put down the watering can!