Change your two trinkets to stamina trinkets.
AN drops a good one from the second boss, JC trinket with dual stam gem for the other.
Once you have that, you are more then good to go for naxx10, naxx25 and most Ulduar fights.
Volunteer to be the add tank the first few times you are there, and you should not run into any problems. (just make sure you know the fights well.)
You've done enough heroics to be sitting on a decent pile of badges - don't. Set a goal and work towards getting it. There's worthwhile gear to be had in each of the three older badge tiers you have easy access to, and if you run the daily often, you'll get enough triump badges to get some of the cheaper stuff from there as well (two cheap items will probably get you more milage then one more expensive item, but make up your own mind.)
Edit: Decided to check your spec. Get judgements of the just.
I'm not going to go into specific gear choices for two reasons. First you need to learn to make those yourself (so you know if that shiny drop is any good), and second because there are a ton of guides around here that explain it really well.
I agree with Martie, Judgements of the Just is another form of mitigation (through slowing enemy attack swings).
I can only offer the following gear suggestions that should improve your survivabillity, other than that, gear should not be holding you back.
SHOULDER: Replace 16def gem with 12sta 8def gem. Work on getting Hodir enchant.
CHEST: Replace 16def gem with 12sta 8def gem.
LEG: Replace 8dodge 12sta gem with 24sta gem.
TRINKET: Get yourself the trinket from H AN and drop that PvP trinket out.
These changes will net you about 200 extra HP unbuffed (doesnt sound like much) through clever use of socket bonuses and gems, whilst still maintaining your defense cap.
You also need to overcome the perceived culture among tanks. Yes, resi helps against reducing critical hits, but enchanting/gemming/gearing for it on your tanking set does lose you points if someone less experienced is overlooking your gear for raids (which will happen behind the scenes, believe me). Your better off going with the mainstream tank enchants/gems/gear for your tanking set to avoid critisism.
Unless there was a better option on the table, your fine for MT in Naxx10/OS10+1/EoE10, and fine for OT in Naxx25. You should also be able to handle some Ulduar10.
Take advantage of your badges, pickup the Platnium Mesh Cloak (valor badges), Tier8.5 BP/Helm (conq badges) and also Kyzoks Ground Stompers (valor badges) and these should put you in the right direction.