CPU spikes to 100% site doesn't load, VPS crashes after moving site

I moved my site to a virtual private server(VPS) because my sharing web hosting account doesn’t support the growing number of visitors, but when i install it, CPU spikes to 100%, site doesn’t load and vps crashes.
I tried everything; desactivating all plugins, deleting all plugins, checking database, installing a fresh copy of WordPress but still the same problem.
I asked my hosting and they said that the problem comes from my site.
i tested the website on two different shared web hosting account and it worked fine.
so the website works on a shared webhosting and doesn’t work on a vps or dedicated server.
I have been trying to find a solution for 3 weeks and i’m getting crazy ,Please someone helppppppppppppppp.