Hi Rendy,
are you running on a shared hosting or VPS with very small amount of memory? It seems to me as though you have reached whatever limit has been imposed by your ISP (RAM or CPU by the looks of it). Could you please give us more information about your setup? Please see here to get an idea of what you need to provide us with to get a meaningful answer.
Off the bat, it seems as though you'll need to shell out for a more robust server.
Cheers,
Fred