please, by looking at the burnt looking leaves is ...

Hey there ATICT , not bad for a first grow without nutrients ! You're right that you've been overwatering, from the start in fact : you can tell from the puffy space in between the veins of the leaves from the start of the diary. So loads of questions there, so i'll start in the middle ? By age of the plant, I do think you mean senescence which is when the plant reaches the end of it's life and starts to show "autumn" or "fall" colors. I dont think it's that unfortunately. Your main question is why do you have a small yield ? there are two main factors in general for this, size of the pot and light intensity. You have small lights, so you're getting a small yield, simple as that. Now about the nutrients, well yeah there is a nutrient problem, but it's not nutrient burn, at least i dont think so because looking through your diary you've not listed any nutrients so it shouldnt be nutrient burn, that and the absence of burnt tips. but you do have a nutrient problem. a few weeks ago when the bottom leaves started turning, that was due to lack of nitrogen so the plant sucked up all it's nutrients from it's own leaves and they yellowed and fell off easily. Second a week or so later the beginning of phosphorous and potassium deficiencies started showing. the plant uses P&K to make flowers so it's common to find those during flowering. you can tell by the "splotches" of color on the leaves and the colorful sides on the leaves, that's how you spot those deficiencies. Next time try feeding a bit of nutrients, when a plant is healthy and wants to grow big they'll usually need more nutrients than the soil can give them. At least i can say your lights were not too close, so that's good right? anyway, i know it's a lot, but i hope this helps ! 🚀