Investigate why my web server became slow and unresponsive

I need a sysadmin that will use teamviewer to get via ssh to my dedicated server and investigate why suddenly this morning it became slow and unresponsive. I need someone responsible that can start right away. If you locate the problem, you will need to provide a solution. This is a live server and I need you to be cautious and chat with me before you do any changes. Understanding this project is essential and you will need to prove that in your pitch. My budget is very small for this.