Hi, It depends on various factor such as which update has hit your site, its might be panda, penguin or even the exact match. check your google webmaster & analytics to see the fall in ranking and traffic and then check which updates had been done on that dates.. its really hard these days to rank on google with small sites, it needs more of a brandable site with good amount of social presence.
Optimize your site with Google quality guidelines and also do some marketing in the search engine like link building and some directory submission. This factor will improve your sites quality and also some of your rank will increase automatically.
If your site are going down daily then first check your website's Backlink and check the content duplicacy, If found duplicate content then immediately remove it and write unique content.