Intrusive thoughts are horrid. I have them frequently. Sometimes they shock me to the point where i freeze. But I don't often act upon my intrusive thoughts although the intensity/frequency of them often leads me to be worn down. I have realised with some of my thoughts they are a visual expression of my feelings. It is like my body has realised it can't express my emotions, and my mind wont compute them verbally so it visually shocks me to try and make me listen. So like the others have said, acknowledge them, the more you face them the less scary they become I have found. Of course you are always going to have a few that are too distressing but maybe the bulk of them can be helped this way?