Site appears in google for nearly 2 days then vanishes for months again - SEO Help

My site [login to view URL] is now Page Rank 3 and for the last year it was ranking on a lot of google top pages for keywords such as cheapest hotels, laterooms cork, laterooms swansea, laterooms london and many more similar ones. After doing some backlinks using scrapebox, freetrafficsystem, article marketing etc it suddenly dropped rankings to either 5-6 pages down or completely dissapeared for many keywords. However it came back 2 days ago and ranked well again until this morning where its dropped considerably again. I really do need help on why this is happening and for someone to please fix it for me so I appear as expected in my rankings. Oh and I am indexed on google i.e. site:[login to view URL] brings back loads of my pages so I don't think i'm being sandboxed???