Could taking Novolin N be the reason for my excessive sweating(cause me to get really weak)?

Your excessive sweating is most likely to be a sympton of hypoglycemia (where your blood glucose gets too low)
This from http://www.drugs.com/mtm/novolin-n.html
"Take care to keep your blood sugar from getting too low, causing hypoglycemia. Symptoms of low blood sugar may include headache, nausea, hunger, confusion, drowsiness, weakness, dizziness, blurred vision, fast heartbeat, sweating, tremor, or trouble concentrating. Carry a piece of non-dietetic hard candy or glucose tablets with you in case you have low blood sugar. "

See also http://www.drugs.com/enc/diabetes.html