First and foremost. You don't have to match gems to the sockets desired color. For example that strength gem, is a NO NO. Not spending the money on your gear that you plan to keep...also a no no....put 2% threat on your gloves. Also put 12 stam on your bracers.
now, for a list of things to do:
wake up, go to shadow labs (regular) farm 2nd boss for adamantite figurine.
do every daily possible in shattered sun rep. get new shield. new necklace.
tank Heroic mech.
find 3 mages and a resto shammy. make them take you to heroic MGT and get a commendation of kael thas If a quickening blade drops, take it. and stop farming mech.
If you have t4 gloves, you can make your way to chess event in kara. farm a kings defender once a week.
save every badge you get for a chest. then save every badge you get for a girdle of the fearless.
find a gruuls pug in trade chat every week and sneak your way into it. get some t4 shoulders, and maybe some legs out of the deal, as a warlock fear tank, and a pro intervene user.
after that 175 badges, get some new legs if you dont have t4. if you do get some bracers of ancient phalanx.
with the combo of the dailies giving you rep, and money spend the money to take care of your new gear.
and please remember your role in your guild. If it is to main tank stack stam gems once you get to where you can let go of the defense gems.