people on this board have talked about the LSAC GPA calculator. is this an actual thing on the LSAC website or just private calculations based on LSAC's system?
Yes it's worth continuing since a lot of people with great LSAT's and low GPA's go to top schools. Also, a lot of schools are pretty aware that when you change schools AND majors and start improving that your first UG school/major wasn't the right fit. Simply right an addendum explaining the situation or the reason behind your move and you should be fine, of course depending on your LSAT.
If your grades changed completely when you transferred schools, law schools would see that and surmise that the first school was not a good fit for you, so an addendum that explains that might not be necessary. However, it might not look good that you had to transfer "down" (no offense but UT-Dallas is just not considered to be on the same level as Austin) to get good grades, so you might want to explain your reasons for transferring - that Austin was not simply too hard for you. What law school would want you if you can't perform at a challenging school?