Oh, I remember when my son took organic chemistry - yikes!! He is 45 now and a senior chemist at Abbott Labs in Chicago. He has a PhD from Cornell but organic chemist threw him for a loop! Hard to stay calm and handle that type of stress. See if you can get extra exercise - that will help.
I have had IBS for about 30 years and stress and certain food can bring on just about anything. Hang in there.
ElaineNY