Your articulate description and narration of what’s been happening reveal your courage and intelligence. You are clear in knowing when the changes happened—what is missing is the why.
I will highly recommend that you ask to begin therapy. If, for some reason, you cannot, I’d make an appointment with your school counselor. The move to Houston is when everything changed. While, of course, it would impossible for me to know for sure the first thing I would have you talk about is the reason for the move and your feelings about it. Often, dramatic changes in a way a person feel and acts and behaves come form a loss that has occurred. I would start asking questions about the cause and the losses that may have accompanied the move. This may or may not unearth some of the hidden reasons for what has been happening, but at least it will rule out these possibilities as causes.
Do not wait. Look to be talking to someone sooner rather than later.
Wishing you patience and peace,
Proof Positive Blog @ PsychCentral