TEXAS: Pulled over, speeding

[Motok1m]

What is the name of your state (only U.S. law)? Texas

I got pulled over and i really was not speeding, dont nw if it matters but this was at 11:34pm:

As I had reached the peak of a hill right as you enter Castroville, I observed 2 police vehicles parked on the right hand side of the street. As I had started to go down the hill I saw a speeding car (the cop) come from behind, in the other lane, and passed me up and later stopped at a stop light about ½ a mile down the street. When I reached he light it was still red, so I stopped next to the cop, the light turned green and I started to drive, but the cop waited and then pulled behind me and turned on his lights. The officer got out of his car and came to the passenger side of my car and asked me for my license and insure. When pulling out my ID from the center console of the car he saw $500 (in $1 bills) in cash and asked me for what reason I would have that much money in my car, I told him I had gone to the bank earlier. He then asked me for a receipt and I responded that I did not have one. He then asked me why I was going so fast, and I told him that I was sure I was going the speed limit. He then asked me what the speed limit was and I responded 40mph, which is the speed limit. He said “no you were speeding because I sure as hell was not going 40”. I asked if he had me on radar, which he said “no, but I paced you”. He then asked me to step out of the car. He went to his vehicle and checked my credentials. He came out and asked my what I was doing in Castroville and I told him I was helping a friend. He said where. I said out near Hondo. He then said “where exactly?” I then described the route to get to her house and what I was helping her do. He then asked for my phone number, where I worked and for my social, which I did not provide my social. He then asked me if there was anything in the car that I should not have such as drugs or illegal weapons, and I responded by asking if he planned to search it. He said he was planning on asking for my consent, in which I responded that he could not search my car. He gave me the ticket for allegedly speeding 60 in a 40 zone, which I signed it. He then told me that he would be calling a drug dog and I would have to wait outside till they arrived. I asked if I was being detained and he replied, “At this moment, you are being detained.” Two more offices along with the dog came later on and after the dog came up empty I asked if I was free to go, and he said I was.

and honestly, i am not a druggie, and i was not speeding. Should i just plead not guilty and go to court? Should i hire an attorney?

and because he started off behind me and accelerated to ahead of me, how was he pacing me if he had to be accelerating? shouldn't he have had to keep a constant speed?

Thanks in advance.