Malibu Motors Sold me a lemon Houston, Texas

I am a single mother,and a student. I work a part time job, and saved $3000 to purchase me a car because my truck had been totaled. I looked online, and came across some cars, the caar that caught my intrest the most was the vechicle I purchased from MALIBU MOTORS. I thought I had a good thing until yesterday only 12 days after my purchase the car ran hot on me, and the mechanic said " you will need a new motor". I contaced the dealer, and the guy who sold the car said " it's youe fault for running the car hot, I drove this car a whole month before you bought it, and nothing was wrong with". I feel like I have een taking advantage of and just lost the hard earned money I saved. My goal is to not get stressed, nor to give up on fighting this until the end! I just wanted everyone out here to know what kind of business MALIBU MOTORS is running, all they care about is them selves, and taking your money. I have never been in this kind of situation before, and I pray noone else has to, money is hard to come by I could have used that money for something else I just didn't want to pay a carnote I do understand the car was cash, and older but it should be somthing that can be done within the state of Texas for consumers within 30 days. I have been told to look into the lemonlaw, and small claims court, and that is just what I plan to do, but I just wanted to world to know what kind of business this is, thank you for your time!