Please accept the kid on your couch as he is. Life happens. Many families relocate for jobs, for many reasons. States need to set residency requirements and you now can claim it for Mass.
Reread post #16. Definitely have son discuss options for schools with his HS guidance counselor. The reality is that you are living in Massachusetts now and Texas is past history. It may be that community college will be the path your son needs to take before a four year one. It is important that he shore up his knowledge and skills base so he can be successful. The journey to long term success often has blips and path detours. Your son needs to show he can do the work he did years ago with future grades.
I never heard of any HS combining another school’s with its own gpa, regardless of the state. Too many variables that it would not be right to do so.