There's nothing wrong with you. You lie, and there's nothing wrong with that either. There's no truth-serum you can take to make you lie less. The only problem is that you feel guilty. If it makes you feel better, you can talk to your therapist about it, but lying to get out of trouble does not make you a pathological liar. Pathological liars do not feel guilty because half the time they believe their own lies.

I don't want to come off as harsh but...don't worry about it. You're fine.