Does one who suffers from obsessive thoughts of insulting and cursing the Divine Being, the Companions, and the Holy Quran —especially upon waking from sleep, and sometimes feeling intent and purpose— exit Islam?

Disbelief does not occur due to stray thoughts so long as you repel them and dislike them. To treat these whispers (waswas), it is recommended to seek refuge in Allah, frequently remember Allah, recite the Quran, consistently pray in congregation, associate with righteous people, turn away from these thoughts, diligently perform the morning and evening remembrances (adhkar), and frequently send blessings upon the Prophet, peace and blessings be upon him. There is no harm in presenting oneself to someone trustworthy in their religion and piety, among those knowledgeable in ruqyah (definition) shar'iyyah (Islamic exorcism), while being cautious of charlatans.