The roots look good...that seedling, not so much!
I can sense you're struggling a little and don't get discouraged! I had a miserable time when I first started growing.
You'll keep hearing the experienced growers talk about "getting it dialed in". This is something we need to do virtually every time we change growing styles, add new lighting or ventilation equipment, and even to some extent, grow a new strain.
First, you need to get your environment dialed in. Make sure you're maintaining proper temps, RH, ventillation, lighting, and air circulation.
Next, get your grow style dialed in. Make sure you have a sound nutrient regime, appropriate sized containers, maintain proper PH, get the best timings and levels of the ebb & flow, make sure you're using a grow medium that's effective, etc.
Finally, get the strain dialed in. Learn how long to veg and flower to get the results you want, how the strain reacts to more or less nutes, how much height she gains in stretch, how she reacts to various types of training, etc.
It will take you some time to get your grow dialed in and if you ask any of the experienced growers they'll tell you that once you do, you'll likely be changing everything up again!