I am really confused by the Enchanter Perk. The way it reads makes me believe that it only improves perks that I learn after putting points in that perk.

Here is the genesis of my confusion:

So far I have disenchanted a ton of items to learn as many enchantments as I can, however, they all seem weak. I figured I just needed to level my Enchanting. Now I am level 92 in Enchanting and have plenty of Grand Soul Gems but my enchantments are still the same.

So then I figured I must need to put skill points in the Enchanter perk which is the first skill in the Enchanting skill tree. To test the results I took a generic Elven Armor from my inventory. Pre-Enchanter skill points I could add the "Fortify Destruction & Magicka Regen" enchantment to it and get these results:
"Destruction spells cost 5% less to cast. Magicka regenerates 10% faster."
That was with a Grand Soul Gem.

I then put 5 skill points in the Enchanter perk which now reads "New enchantments are 100% stronger."

When I go to check the improvement of the Fortify Destruction & Magicka Regen enchantment I am pained to see that it still only offers the same stats as before the skill points.

Am I missing something?

I guess my question boils down to this:
Did I screw myself by learning a ton of enchantments before investing the Enchanter Perk? Do the effects only apply to "new" enchantments I learn? And if so? How am I supposed to improve the results of all the enchantments I've already learned???

Sorry for the rambling question, but I am really confused and a bit defeated.

Did you choose a soul gem?

It will show a default value until you choose what soul gem to use, then it will tell you how much the enchant with that soul gem+your skill+perks will do.

yea this. And if im not wrong, that enchantment is bugged, the 10% destruction thing will remain at 10% whilst the mana regen will increase. Either that or its the other way round.
still the most important thing is the double enchantments Try using a simpler enchantment like fortify destruction; it should be at 25% max.

What hermit said, plus you might invest in some enchant potions... and enchant a special set of clothing and jewelry to fortify enchanting.

Choose different enchantment, and make sure you've selected everything.