You should contact your lender about all deferment options, and to get the appropriate deferment forms. The cost of the Co-op program is included in the tuition. You will need money for living expenses, which is generally expected to come from your earnings over co-op. There are some scholarships available for co-op as well. Co-op stipends will not replace any other aid.
Students have to reapply every year for the next year's aid award.
If your situation changes from one year to the next, it may affect your aid eligibility. For instance, if your family's income goes up, your aid eligibility may go down. If the number in your family changes, or the number who are enrolled in college changes, that may affect your total eligibility. Your parents' marital status will affect your aid eligibility if that has changed during the year. There are also some other reasons that aid changes.