It's your web server that's borked. Speak to your hosting provider.
Slowness is not evidence of a hack, just a poorly tuned web server. You could be hacked but just that alone doesn't indicate anything.
When you visit your site with another web browser (meaning you have not logged in) do you get anything like additional spam links? Any odd redirects?
When you disabled all of your plugins and switched to the Twenty Eleven theme, what kind of results did you get? I mean in seconds.
This page loads fine. http://blog.redmanc.com/readme.html
This page loads like death itself. http://blog.redmanc.com/
The first is a static web page, the second engages the PHP interpreter and that appears to be where you are enjoying a slowdown.
You can see the speed results here.
http://tools.pingdom.com/fpt/#!/LNuVQdf0T/blog.redmanc.com
One last test: on the CLI telnet blog.redmanc.com 80 and type in anything and hit return twice. A web server should disconnect at the bad request.
Your's doesn't. Try the same test on my site or others telnet blog.dembowski.net 80 and hit enter twice after typing in anything. You'll see a 400 Bad Request reply followed by a disconnect.
Talk to your host provider, something odd is going on with your web server.
Edit Forgot to mention: when PHP does finish creating that page, you get this in the HTML.
<!-- 37 queries. 75.436 seconds. -->
That's a bit long, that server is not well.