Chances are extremely slim to be appointed at this point given you have received an AOG Scholarship. I would recommend focusing on the prep school choice and getting that option squared-away while the class of 2023 finalizes. Good Luck!
Check out this FAQ from this past A-Day. Might help answer your questions.
https://www.usma.edu/sites/default/files/pdfs/General/Parents/ACCEPTANCE%20DAY%20FREQUENTLY%20ASKED%20QUESTIONS_2018.docx.pdf
I believe, and I might be wrong, but if your DS is a sponsored by one of the academies (to NMMI, MMI, etc.) then they will qualify and receive an ROTC nomination provided the prep school had them fill out that paperwork.
Texas-05 nominations are out and I saw from another post (Two MOC Nominations to the same Service Academy) that Senator Cornyn's might be out. Nothing on Senator Cruz.