OCD Question

I wasn't really sure where to post this, but I figured since OCD relates to anxiety, I might be able to find some help here...

anyway, I have been struggling with intrusive thoughts common to OCD. Basically, around once a month, I have a week or two weeks where I experience almost non-stop intrusive, inappropriate and unacceptable images in my mind; the only way I can stop the images is by saying a specific prayer over and overor by calling up a different image in my mind. These thoughts cause me extreme panic and anxiety, they cause me extreme guilt, they make me feel like I don't deserve anything in this life, and I am so afraid that the people I care about might die or get hurt because I can't control my thoughts.

I want to know how I can make these thoughts stop. They are not me, I hate them and I would never think something like that;I feel so ashamed of them, and the harder I try to control them, the more my mind fixates on them. I just really want to know what I can to do to make them stop. Any advice would be greatly appreciated.

Thank you.