Texas Grant or Texas Public Educational Grant? They are different.
Is Stephen f Austin, Sam Houston and the university of Texas at Arlington finaid better?
The Emerald Eagle Scholar program looks like a dream option but even without it you still did not exceed all the possible aid.
Did you apply for work study? (you have to check something in FAFSA)
There are no loans in your packet. There are different types of loans: Stafford, Perkins (available at some universities, not everywhere) and B-On-Time (the best one, will be forgiven/turned into grant if you graduate on time)
You don't qualify for Top 10% scholarship (it is 2,000 a year with a pretty high GPA requirement, so many students cannot keep it all 4 years)
Plus there is always an easy way to reduce actual COA from the estimated one by buying used books on amazon and finding cheaper housing not on campus, by $2,000-3,000 easily, more than $3,000, well, depends... I have never been in Denton to say anything for sure.
Plus there is always way to make money over summer. If you are already 18 try to find a work as a waiter, the more upscale restaurant the better. If you work really hard you can earn enough money to cover the difference (depends how upscale the restaurant is).
If you are still a minor, restaurants will have issues with alcohol serving and will not hire you. Other jobs... well even with minimum wage 3,000-4,000
I really don't see any problem with this situation at all.
Start with summer job. Whatever you make will be your own money, and you need your own money.