mmoamen i suggest you to use "reverse proxy"
what you need is 2 separate server
1 to shown to public,
and the another 1 is to handle the sites data (real host)
example you had yoursites.com ip 1.2.3.4
instead showing 1.2.3.4 ip you showing 5.6.7.8 ip,
so all connection must go to 5.6.7.8 before handed to 1.2.3.4 from reverse proxy
with this system you will safe from any ddos and even from DMCA if it allow
if you want something about it, you can contact me on telegram @Dhanamerdeka lol, but of course not free XD
but if you want it to be free, you can follow tutorial by our fellow aapanel member on this forum, one of them already do the tutorial for it