Switching from Unholy to Frost was probably the best WoW decision I've made. With what little T11 I experienced with Undying Resolution, I constantly grazed the bottom of the DPS meters. Coupled with my poor survivability, I was totally a candidate for bench warming instead of experiencing content, which frustrated me into wanting to improve in whatever way I could.
I ran countless amounts of dungeons with Amowrath; he's a Blacksmith, so while he'd collect Orbs for crafting, I was honing my skills. Little by little, I was dying less. I learned how to get the fuck out of the ick, when to pop my survivability cooldowns, and how not to pull aggro from tanks whom I outgeared. I went from pulling 16k DPS on a GOOD day to averaging around 22k. I'll always be grateful to him for being up for running with me whenever, those runs were a valuable learning experience.
Then, came the actual raiding process. I spent the entire tier anxious to prove my worth. There were times where I wanted to throw my hands up in frustration and bow out due to stupid mistakes I made -- "Derp Kn00b" moments such as Death Gripping the wrong Elemental(s) on a Rag progression night which caused us to wipe during every attempt I was in, dying repeatedly to the Fiery Tornadoes on Alysrazor pre-nerf because of my shaky nerves, and of course the bane of every melee DPS' existence... standing in it.
I picked up PvPing to help with my survivability (aka more "get the fuck out of the ick" training), made a focus macro to follow around a talented guildie during the Alysrazor tornado dance (ain't no shame!), and learned a tough lesson from my embarrassing Rag fail -- from that day on, I made sure my positioning was precise and I never let another Elemental I was responsible for touch the hammer.
As I learned what I was capable of, my survivability rose from around 60-70% (yikes, right?!), to the high 80s... and onward to 90+ by the end of the content. I was finally an asset to the raid, instead of a friendly liability.
<Insert Spine Kill Image Here>