Hello guys n gals... i jus came bak to WoW from quiting awhile ago

Nowadays all ppl look at are GS n achievements... GS i get it, it's a must to be adequately equipped to survive the raids... and one can get the needed gears when they spend some time
But ACHIEVEMENTS?

First of all, my guild's a super casual guild which dun raid at all... so i cant ask any1 to carry me. that's ok, i used to pug ulduar n toc all the time
Secondly, now the ICC's got 12 achs... and i quit when i only got 4.... and ppl dun let u in unless u got 6 or more...

How can i get MORE... when even PUGs need 6+...

i know all about the fights from reading guides n watching youtube videos like tankspot, but ppl wont gv me a chance, it's not like performing a surgery, u cant learn it only by watching a video... i've raided much too.... argh.... getting carried away here 
    anyways to get ach? i dun like to use something like achievement hack... but if it's the last resort, i'll use it