Why does one with a discharge perform ghusl for every prayer out of fear of breaking their wudu, and what is the way to get rid of this thought despite continuous attempts?

The fundamental principle concerning the body is its purity from major ritual impurity, and janabah (definition) (state of ritual impurity due to sexual discharge) is an incidental occurrence. Semen does not exit merely by thinking, but rather upon the intensification of desire. If semen did not exit with certainty, then ghusl (definition) (ritual bath) is not obligatory upon you. And if you doubt whether the discharge is semen or not, ghusl is also not obligatory upon you. You have the choice to consider it either semen, in which case you perform ghusl, or madhi (pre-seminal fluid). This is the view of theShāfiʿī school. It is advisable to disregard whispers (waswās) and not dwell on them.