Hi, you have described symptoms suggestive of Obsessive Compulsive Disorder. It is possible that these symptoms increase and decrease for you with life stressors like exams etc. My suggestion is that you consult a Psychiatrist at the earliest. You can definitely benefit from medication and counseling including cognitive behaviour therapy. Hope this helps, All the Best!

Your current symptom description matches a particular psychiatric diagnosis. Its better if we don't label your condition right away and needs further evaluation into details like onset, your cognitions and other associated symptoms at the earliest so suitable treatment can be started. Good luck!