It sounds like your skin may have reacted after using neem oil, especially if it was too strong for your skin or applied repeatedly. Sometimes oils can clog pores or trigger irritation, and the intense itching with new pimples can also happen if there is an underlying allergy or even a skin infection that has been aggravated. Stop using the neem oil for now and gently wash the affected areas with a mild soap and plain water. Try to keep the skin cool and dry, and avoid scratching even if the itching feels strong, as this can spread irritation and lead to infection. Wearing loose cotton clothing can also reduce friction on the skin. Since the itching is severe and widespread, it would be safer to get examined by a dermatologist. The exact treatment depends on whether this is an allergic reaction, scabies, or another skin condition, so proper diagnosis is important before starting any creams or tablets. Seek medical help urgently if the rash is spreading quickly, becomes painful, or you notice fever or pus-filled bumps.