I find this amazing that it is so difficult to get the point across. Here's some great theorycrafting.
You have mana issues.
The people trying to help you aren't having mana issues.
You use Regrowth.
The people trying to help you don't use Regrowth.
You want advice on not wasting your mana, you ask people who don't have mana issues. They tell you what is wrong. Why so relucant to accept advice when you yourself admit, in your original post, you have mana issues?