direct admin and linux vps expert needed to check why my vps is constantly failing

I am looking for a direct-admin and linux vps expert who can do a check on my VPS (check settings, logs, traffic, load, fake bots, etc.). I need to reboot my server regularly because it goes out of memory (512MB with 1024MB swap memory). I have maybe 10 sites running on it, but they total to maybe 100 or 200 visits per day according to Google Analytics. However in the serverstats I see googlebot 2.1 coming as 90% of all visits, while I've indicated in Webmastertools just to visit once every few minutes (but this doesn't seem to happen; fake bot?). I just don't understand why my server is failing all the time. It is my hosting company that does something wrong? Is it my setup? Is it spam traffic or bot visits that are killing my server? Is my server too light? I need an expect to look at this for a few minutes.