Don't you just dislike it when you feel guilty about something? Sometimes we feel that it is our fault when things go wrong and it just makes it guilty. What is more difficult is that you feel helpless. You don't know what to do about the situation to change it or make it better.
When you feel guilty and feel helpless, you feel weak and it's frustrating. You tend to worry a lot and think of a lot of things - a lot of what ifs. How then should you "unfeel" these kinds of feelings and thoughts?
One thing that helps is praying to God. There are things in life that we question a lot and we can't find the answer. Let God worry for you. When we totally surrender everything to Him, our burdens will be lighter. Be willing to let God work in you and help you.
"Be strong and courageous. Do not be afraid or terrified because of them, for the Lord your God goes with you; he will never leave you nor forsake you.” (NIV)