Gpu thermal pads make my macbook sluggish?

[Reiza Angga Hadikusuma]

hello all, can you guys solved my problem, i’ve got my macbookpro retina late 2012 so laggy and sluggish, then i check my monitor activity my kernel_task gettin 300% and 90% cpu by system 10% by user my fan runing normally not in boost mode like a plane try to take off, i try to modified the .kext it doesnt solved my problem, i have chek and clearly my machine from dust and no water damage on my logic board but i find some piece look like thermal pad on my gpu chip is gone,

Can some one tell me the name and where can i get this part

sorry if my english so bad english is not my daily language.