need database and wordpress proffiesional Guru for high load issue

{{{ Please read it carefully before you contact me }}} since 7 days i fight with my site issue which is very high load (almost 250) my site is wordpress with 3 cores and 4GB ram server and worked fine for almost 3years after a lot of tests and fixing i find that the issue comes from database because i uploaded new fresh installation v3.8 and create new database name and site works fine and too fast but if i added original database (which has posts and comments content) load goes too high so fast and site went down so now i stop httpd service (apache) and enable light speed http to prevent load because i got warning from hoster provider again and again if u r not a perfect programmer in mysql database and wordpress pleaaaaaaaaaaaaase don't bid