I think the first thing you could do to help your situation is to switch to dry ferts go to an EI dosing regime or a modified EI dosing regime. Your all-inclusive fertilizers are great up to a point, but they have been dumbed down to a level for the average consumer. As a consequence, you're probably underfertilizing your tank.
The good news is there are a number of guys on the forum who will provide you with the dry fertilizers that you need. The easiest way for me to deal with dosing dry fertilizer is to scoop it into the weekly pill containers that you can pick up in any pharmacy. A single daily dose of macros (NPK) go in one compartment, micros and iron in the next, and so forth. This gives you a week and change for fertilizer dosing with each planner and filling the little containers takes about 15 minutes for three weeks' worth (three weekly planners). At that point, the only thing you have to do is open the lid and dump the fert.
Fertilize as normal after water changes.
Next, consistent water changes are the key to healthy aquariums. For all practical purposes, it's like hitting the reset button. If you're scraping algae, scrubbing walls, and manually removing algae from plants, don't be afraid to change 75% of the water. At that point, you're manually removing the stuff that you want gone.
Finally, consistent CO2 will help you a lot. You may find that adding more DIY containers and setting up a rotation where one container is petering out, one container is running wide-open, and a third container is ramping up will give you the most consistent results. From what I have read and what I've seen on the forums, DIY CO2 is pretty difficult for tanks over 30 gallons or so, but not impossible. In the end, you may find that pressurized C02 is the way to go. One last note on CO2- once you're committed, you're committed. If the gas runs out, get ready for a world of hassle.