can't install nginx module!

i use CentOS 6,6... i use the latest webmin version and everything up to date...

my website been offline since month, i used apache but it ate all RAM i have 1GB ram and it used my whole CPU, i only had between 100 to 250 pages views per day, and i don't run much modules on my VPS 4 or 5 only i run wordpress website, i tried to optimize apache and mysql but it did not help at all, so this why im here trying to run nginx for the first time, my website been up and running for more than a year and everything was working fine during the year but when i start getting more pages views my website start to be very slow to respond and sometime takes 15 minutes to load a web page...so im here asking for help.....

i learned about webmin and virtualmin all by my self for the past year, i learned too many things, i rarely ask for help...but seems this time the problem is not from my side because i'm trying to install a module from here and it tells me [no package (package name) available] so is the file no longer on your server or you stopped providing support for nginx module or there is a little problem from my side??? where are you all people?!