What is the ruling on the tension accompanied by the sensation of semen being released, or its actual release, when saying the Takbir or sitting for the Tashahhud during prayer, and does that affect the validity of the prayer, and how can one get rid of this Waswas (whispering of Satan)?

You must strive against your soul and resist the whispers (waswas) to overcome them, and avoid abandoning prayer due to its grave sinfulness. It is also advisable to try to calm down and not pay attention to intrusive thoughts and ideas. Consulting trusted doctors may also be beneficial. If something is discharged after every prayer, then it is necessary to perform ablution (wudu') after the time for prayer begins, and pray without paying attention to what is discharged, just like someone afflicted with سلس (incontinence).