How can one get rid of obsessive-compulsive thoughts concerning creed, which involve insulting and inappropriate fantasies about the Divine Being, and which have led to a feeling of aversion to worship, fear of atheism and God's wrath, and thoughts of suicide?

What you are suffering from, in terms of intrusive thoughts (waswas), is from the machinations of Satan, and you are upon goodness, love for the religion, and righteousness. Do not despair of Allah's mercy, for these intrusive thoughts do not harm you, and your hatred for them is proof of the sincerity of your faith. Strive against these intrusive thoughts by seeking refuge in Allah from Satan, the accursed, and say: "I believe in Allah alone." Cease thinking about them, and exert yourself in supplication, for you will be rewarded for your struggle against them.