Advice for a bad driver in Houston

can someone please give me some advice how to drive in Houston so I don't get killed?

I recently relocated from the northeast and admittedly I am a terrible driver. In the northeast, whenever I merged into the highway, as long as I "blinked", most of the drivers would simply yield to me and let me merge. I have since relied on people's courtesy and have a bad time using the mirror when merging. However, ever since I moved here, I have had multiple situations where the drivers in the highway speeded up right past me instead of yielding me to merge. There were times when I almost crashed into other people's car. What should I do to be a safer driver in texas? I have also changed the car insurance to TX and I am surprised for the same coverage in texas, it costs nearly twice the amount I was paying in northeast with Geico. should I look into some local car insurance companies? is there any recommendation?