My first thoughts are your total avoidance are a bit low. I think your total health pool should be large enough to look at regemming and changing up your weapon rune from SSG to Shattering.
To avoid haphazardly changing out all those Stam gems and/or enchants for defense try plotting out what it'll take to keep you at or above the 689 defense rating. For starters I'd suggest swapping out your shoulder enchant for the Sons enchant. As well you can probably just swap out a few of the stamina enchants to defense for best results without dropping your health pool that drastically. And if you're regemming pick up some Def/Dodge or Def/Stam gems if you can spare them instead of straight Defense to stay at the 689 rating threshold. But overall the effort to pick up the 4% parry straight out will be a big boost.
Id say stick with the SSG on your weapon, cuz atm theres no way you can just enchant your gear with def and expect to replace a straight 25 def without gemming most if not all your gems with pure def. My suggestion is trade out all your stam gems for dodge gems, and stick with keeping the socket bonuses, just gem accordinly. (Remember, def is still good above cap, though we don't get +block value you still gain +dodge, +parry, and increased effect from IBF)