You are just panicking. There is no need to fret so much as analysing power of your brain, as u put it, cannot just get lost, its temporarily out of service because ur anxiety has overworked it and put it in this condition. Anxiety plays havoc not only with your analysis power but also memory, attention, output and your physical wellbeing
Next Steps
please relax, take time of, don't experiment to see if your brain is working correctly by giving it rapid fire questions, maintain a healthy lifestyle, excersise correctly,have regular mealtimes , talk out your anxieties with your friends and organise ur work. if this doesn't work consult a psychotherapist. but before anything else go for a vacation. a vacation now will help fill the vacancy of ur mind.
Health Tips
1. be kind to yourself
2. balanced life, allotment of time for both work and play , is the key
3.take breaks in between studies