I have constant fear that my sertraline 75mg medicine is going to make me go crazy. constant worry, anxiety and scared it will happen to me. on mnth 3?

No,: it doesn't make people go crazy. The most likely possibility, since your dose of 75 mg is low, is that it is insufficiently treating your anxiety. However, there is a small possibility that it is increasing your anxiety. YOu should sort this out with your doctor.

Just the opposite: The average effective dose of sertraline for anxiety in my patients is between 200 and 300 mgs daily. 50 - 75 mgs daily is a good starting dose, and then I increase the dose gradually. It will actually ease the anxiety as you get to the higher doses, not make you worse. Please discuss this in detail with your doctor.