VPS Being DDoS'd

I have got pretty big problems with my VPS, some of my sites getting DDoS'd a log. I have no idea why and who DDoSing them

I have csf, apf and DDoS Delfate installed but it seems they can't take those attacks down. I know for mod_evasive but it works only on small attacks, I getting pretty strong attacks

I need some way to configure csf better, what I need to edit in /etc/csf.conf to block IPs if the same IP trying to connect to server more that 10 times. I need everything what I could edit for csf to block IPs faster

About DDoS Deflate, he is configured to works with apf, can I configure it to works with csf and how? How to configure DDoS Deflate better, to block IPs faster

Also, another problem with csf is that when I restart csf(service csf restart) he unblock all blocked IPs and I have to block them again

How to see blocked IPs by iptables?

I running lighttpd at the moment but I thinking to change it with Litespeed(free edition), what do you think about it?

I hope I will get some help here. Aslo,would be interesting to hear how do you guys protecting your servers from DDoS(if you getting DDoSed