Ford Lynx

I hit a rail track and bumped the under side of the engine. I stopped to check and restarted. After that, I noticed a different sound, its like a race car sound. I stopped again to check the muffler, but it wasn't from there. It was from the front. After that, I noticed that my air conditioning got hot. I did not immediately brought my car for repair. It sit on my garage for three weeks. After that the batteries are drained. My cousin tried jump starting it but it can't sustain. A friend of mine suggested that a ford lynx's computer needs to refresh. Once you got a problem, everything else will be affected even if it was not included with the primary problem. Is that true? And what do you think about it? Am I in big trouble? Should I be prepared for a big spending? By the way, I am from the Philippines. Thanks.

Liz

PS. Initially before the incident happened, I noticed that my car was******** on a higher speed. The mechanic said that I need to change the fuel filter since it hasn't been changed for a long time.