u/GustingGrimoire

I'm new to citrus and trees in general. I git this lemon tree nearly 3 weeks ago in a 4 inch pot. I did accidentally let it dry out once and it started to droop, however it has not recovered from that droop. It's since been planted into a 6 inch pot with this soil (pic added) and has been fertilized once. The room it's in is about 80⁰F with 60% humidity and a 12 hour grow light. I don't believe I've covered the root flare?

I just can't think of why it doesn't perk up, even after a fresh water and I'm so scared I will kill it. Any help from experts is appreciated.