There is a reason you are getting these thoughts. There could be an energy blockage causing this.. I know from experience -- before I got into QiGong, in my case it was all the emotional stress in my life built up. You can remove the blockage, but you can't remove the bad thoughts easily. You must recognize them for what they are and do not allow your mind to get "sucked into" a tangent of them. When you recognize a negative thought, change your thinking or visualize something else -- PREFERABLY something you like or anything positive. Over time, these thoughts will diminish, and go eventually go away. What you are thinking affects what you feel -- based on the thoughts you are allowing to enter your mind. Think of something that makes(or has made you) angry and you will begin to feel angry. Think of something that makes you feel happy and you will begin to feel happy.

If you are like me and used to store emotions, here's a tip that will dramatically help. When you feel or think of something you don't like, throw it away and change it. Remember, YOU are responisble for what you are thinking, which affects what you feel. (This works in 100% of all cases. If someone throws a brick at you, you get angry because you CHOSE to be angry. Never forget this!

I hope this helps!