Personly id change the gravel to either sand or a specific planting substrate. How large are the individual gravel pieces?
What plants did you bring home? Some cannot be safely planted in the substrate. Among those that have rhisomes that need to be kept above the substrate are two common low light plants. They are anubias and java fern. For those you tie the crown of the plant to a piece of driftwood or something similar with some fishing line. The roots will grow down to meet the gravel and you won't end up with a dead plant. This mistake could be another reason you heard people talking about losing plants in 4 weeks.
Bogwood would be fine to tie java fern or anubias to. Hornwort does not need to be planted but you can stick an end of it in the gravel if you want to. The valisneria is not really low light but it might survive in your light, it will make use of the root tablets. Crytocoryne is mostly a water column feeder but can use nutrients from the roots. Don't go crazy with fertilizers. Some of the best long term growth that I have seen in low light situations is just making use of the fertilizer that the fish provide with their wastes. I dose mine occasionally with trace elements only but the main fertilizer in my low light tanks comes from the fish.
I would cut back to no more than 1 a week rather than the 2.5. That way if the plants don't use it all, you won't poison your fish. If the cloudiness goes away and the plants are growing well, you might have found a good balance. If the cloudiness does not clear, I would stop dosing entirely for a week or two and see if that helps. I have never had enough ferts in my tank to cause any cloudiness.