You know that the sforim say that the more terrified you are about having a dirty dream tonight, the more likely you are to have one.
The assurance that Hashem
will actually protect you after you saying Sh'ma and tehillim is actually far more valuable than the Sh'ma and the tehillim themselves, are! For, the fact that it calms a person down, removes their unfortunate focus on their porn memories, their penis, and their terror of sperm. No wonder many people in recovery report not having wet dreams in decades!
May Hashem help you relax and let Him take care of you completely....and relax.
Oh, and smile a lot more. You are a good guy!