Just reread and realized your work study was included in your amount. But also showing you, you can make more of needed. My son took 18 credits, worked and played sports and started an organization on campus. It can be done. But of course don’t let it affect your grades if you can help it.
Since you are so close talk again to financial aid. Your package is usually not finalized till a bit later and your numbers should adjust. They also make mistakes. They made one on us and quickly fixed it within a day. As stated, politely let them know your situation. They don’t want to lose you either. See what you can work out to make it happen.
Also seek other avenues for money like your church (or the like), other organizations that would make make sense to you. Talk to your principal /counselor /teachers. Someone might have an avenue for funds that you might not be thinking about.