Help! Server overload problem & not sure what to do

WP 2.7.1, been using WordPress since like WP 1.5 (long time, all on the same host/server).

My site went down. The host said they suspended my account because, something like, it was overloading the server, too many MySQL requests.

They unsuspended me, and I deactivated most of my plugins. The site is back up. I started re-activating all the plugins. I can see the site is slow. I asked the host again, and they said this:

Here is Netstat results for IP address of your account. There are many local HTTP connections (although they are not established now), so I do recommend you to ask your webmaster to double check your scripts and fix the issue;

Ok, first of all, I can see that I probably need to change hosts. This host has been fairly unhelpful in resolving the problem. They only tell me to “fix my scripts”.

But I would like to understand the problem. I would like to ask the host the right questions & give them a chance. I would rather stay with the same host, and not lose the payment I already spent for this year’s hosting, and not go through the trouble of moving, unless necessary.

What would you ask the host, if they said you were overloading the server with too many requests?

How would you diagnose it? How would you track down the problem? Is there some kind of “log” that I can get from my cPanel, or I can request from my host, that will tell me WHICH functions (indicating which plugin) is causing the overloading problems?

They sent me that “Netstat” report and it’s basically just a list of IP addresses. It doesn’t say anything about which function, which PHP document was making the requests.

What should I ask the host, or what should I do myself?

Would it matter if this host/server is still using some flavor of PHP4?

Does this sound like a problem with 1 or more of my plugins, or a problem with the server it’s running on, or a problem with WP 2.7.1 (I doubt it), or have I been hacked / security issue?