Hello
the above mentioned symptoms are indicative of examination anxiety. Try deep breathing exercises and meditation to relax and calm your mind. try to make a time table by dividing the time equally for all subjects along with enough breaks in between. Also practice sample papers and do revision by solving last year's papers. Also you can try consulting a clinical psychologist for better management of the symptoms.
Next Steps
consult a clinical psychologist
Health Tips
meditate and exercise daily, make a time table, practice a lot