It happens dear , nothing to fear , it’s common to experience these at one point of time during neet neet prepration,no worries 🙂
It happens due to lack of mental stability and rest.
Practice some daily exercise , breathing exercises, yoga and introspect your strength and weaknes
Always keep your self motivated , take breaks and spend time with your family and friends
For neet prepration
My dear for Biology Ncert should be your Bible.
For chemistry particularly organic and inorganic ncert should be your Bible
For physical chemistry and physics practice standard modules and ncert all questions whether of chapter end, examples,or in text questions as you have to practice a lot of sums and read theory portion
Try to solve last 10 years MCQ questions.