Website Traffic going down dramatically from average 15000 visitors per day to 2500 visitors per day?

[Ahmad]

my website http://www.VUsolutions.com's Traffic going down dramatically within a week from average 15000 visitors per day to 2500 visitors per day, even there were lot of keywords in which my website always comes in first page of google search in top 5 searches link, but now my those keywords and posts also not shown within 10 pages of google search result. even more than 30 keywords are very good performing for me in past but now everything goes down very surprisingly way. all of my traffic was from google (almost 80%). i dont know what is the reason of this fall, i m very worried, pls any body tell me the reason and suggest me some resolution of this problem, due to this traffic fall my alexa rank now goes to 1236 which was 410 in last month. even i have not change any setting or any other things, it happened automatically. PLS HELP ME PLS HELP