If I were interviewing you in person I would inquire about whether your mental health symptoms are under control. My sense of the situation is that they may not be.
The disturbing images may be a symptom of one of the disorders that you were diagnosed with, obsessive-compulsive disorder (OCD). It is not uncommon for individuals with OCD to experience disturbing images about someone they are worried about. These images tend to be intrusive and difficult to control. A common type of intrusive thought associated with OCD is feeling unrealistically responsible for the well-being of another. This seems to be similar to what you are experiencing.
I would recommend consulting a mental health professional about your symptoms. You may never learn their origin but that is not the goal. What is important is their removal.
You did not say whether you are taking medication. If so, your symptoms may be a sign that a medication change is required. Modifying your treatment plan may be necessary.
When these images occur do your best to focus on something different or positive. Some ideas include watching TV, playing a video game, calling a friend, listening to music, and so forth. The idea is to distract yourself so you can’t focus on the disturbing images.
Your symptoms may be indicative of an untreated mental health disorder. I hope that you are able to get the help that you desire. What’s most concerning about this situation is that you mentioned suicide. If you feel that you may harm yourself, then it is imperative that you seek help immediately or call 911. Please write again if you have additional questions.