Can I be guided and advised regarding my severe OCD, which has led me to doubt the existence of Allah Almighty, and to fear the evil eye intensely, knowing that I have become certain that Allah Almighty will save me from these obsessions?

Hating the whispers of Satan (waswas) is a sign of faith. As long as you repel it, you will not be held accountable for it; rather, you will be rewarded for it. There is no blame upon you for fearing the evil eye, as long as you say "Barakallahu feek" (May Allah bless you) when you see something that impresses you.