Let’s see the roots. My guess is you’ve damaged your root system by way of your medium(whether it be ph, nutes, etc). That coupled with a topping seems to have stunted you big time.
Initial cash outlay with LED is far from “the best”. HPS has and serves its purpose. LED is the future, but the cost disadvantage will take years of grows to recover and by that time, you’ll be needing a new LED anyway. And for the “diy led” argument, it’s irrelevant. Apples to apples