At age 22, there may be some alternate schools that can help you to complete graduation requirements for Alabama. Call the school distrcit and ask about any community college programs that will fulfill the requirements. (See the Alabama requirements for high school graduation) Talk the counseling department at your community college for more information. This would proably be the continuing education dept.
If you have a few credits to fulfill, completing high school makes sense. However, if you have more than a year of credits to complete, consider taking a GED and then enrolling in a community college.