First of all this girl isnt your property and you arent hers. Text messaging is one of the dumbest ways to communicate.Theres nothing to base the message on other than some dumbed down crypto typing.
Cant replace her?Is she a car? Is she a piece of furniture?
Trust issues yes.You had no business going into her account and saying 'my bad' is not an apology. 'My Bad' not even worth the time to type or say. People seem to be getting more and more immature instead of growing up.
Move on.Your young and you have a lot of growing up to do.