The first step is to find out what you have installed. I wrote a little diagnostic program to help show what might be causing these problems. Download EtreCheck from http://www.etresoft.com/etrecheck, run it, and paste the results here. EtreCheck is perfectly safe to run, does not ask for your password to install, and is signed with my Apple Developer ID.
Disclaimer: Although EtreCheck is free, there are other links on my site that could give me some form of compensation, financial or otherwise.