System: Xbox 360

The predicament:
1. My one-handed weapons (excluding daggers) currently do NEGATIVE damage. I'm not looking at comparisons at the bottom of the inventory screen, just to be clear. (I'd post a pic if I knew how)
2. Fortify Destruction enchantments don't work properly. I have 100 in enchanting with 5/5 in the Enchanter perk. This means my fortify destruction reduces costs by 25% apiece. Unfortunately wearing all four pieces of equipment w/ the enchantments only yields a 50% reduction. (necklace, ring, helmet, armor with 25% reduction each should be 100%; y'know 0 cost destruction spells.)
3. The problem has been isolated between these two things. I made a set of armor to reduce costs of conjuration to cost 0 and was successful. Two-handed weapons remain normal and can be fortified w/ enchanted equipment.

Background & reason why?:
I made a set of steel plate armor and enchanted all pieces with two effects: most importantly I enchanted them with fortify destruction and one-handed on whatever pieces allowed the enchantment. It totalled to 160% increase in one-handed damage (currently level 77 in, no perks).

There it is:
The set of steel plate armor had enchantments in place to reduce costs of destruction spells to 0 but instead only reduces to 50% with all 4 pieces equipped. Individual pieces are still proportional in that they, instead of 25%, reduce costs by about 12% (1/4 of 50% if you're following my rant)
Also, again, a 160% increase in damage with one-handed weapons. The effect is applied properly but the weapons no longer give the correct base damage. Example: My Dawnbreaker now does -19 damage. A 160% boost brings it up to 7 damage.

Everything was fine till I loaded a save (after turning on the console) while in Proudspire Manor (Solitude home). The armor was equipped at the time.

Note: The problem doesn't effect earlier saves, unfortunately for me, the closest save was 10 levels and the thieves guild questline back! Hoorah...

Sorry for the rant:
The question remains though: Why does my fortify destruction enchantments not work properly and what caused my one-handed weapons unfortified damage to be in the negatives? More importantly how do I fix?

Thanks for your time, sincerely,
Alexander

disease

There is no diseases under my active effects (or any other negative effects), but I did go to a shrine for the blessing to double check. No change unfortunately.

Try removing, and then re-equipping the armor and jewelery.

I've done all the basic steps to try to remedy the problem: equipping and re-equipping my items, selling the items to get rid of their in-game data, reloading, shrines, making a new set of armor (w/ same enchantments) but the problem persists.