I too suffer from similar obsessions, mostly violent. OCD will always present to you the worst possible thing at the worst possible time. Strangely, the thoughts themselves are not really the problem. At some point we all started reacting to the thoughts as if they meant something. The truth is that they don't really mean anything at all. They are just thoughts, they are not you or who you are. This is very difficult to believe since your OCD will tell you otherwise.

If you can't afford a therapist, I really think you should read "Imp Of The Mind" which deals with this particular vein of OCD.

You aren't alone in this.