I think intrusive thoughts and guilt go hand in hand. Guilt over what the thoughts are, that you can't control your own thoughts, guilt for not being 'perfect'.

I second what was posted above - talking to a mental health professional will give you the best results. Or if that's not an option, research methods on how to cope and fight OCD back. My t recently gave me pages from a child's coloring book about how to overcome OCD and it's been surprisingly helpful.