What is the treatment for someone who has obsessive thoughts that if he speaks to anyone, he will see their awrah (private parts), which leads him to isolate himself from people or lower his head while speaking, knowing that these thoughts only came to him after repenting from his sins, especially masturbation?

Obsessive thoughts can be treated by consulting psychiatrists. These mentioned fantasies are mere extremism and pure obsession. One whose 'awrah (private parts) is covered cannot have it seen, and it is customary for the speaker to look at the face of the person he is addressing. It is wrong to confuse these obsessive thoughts with commitment to the religion of Allah, for commitment is good, and these obsessive thoughts are from the wiles of Satan. One should turn to Allah, ask Him for guidance, and be mindful of Him in secret and in public.