Satan knows that your mind is still the same so he try's to attack your mind. The battle ground here on earth is for the control of your mind. The only weapon satan has is to attack you thru your thoughts. He tries to discourage you by telling you about all of your failures, sins, wrong choices and bad relationships you have had. He wants to take control of you by controlling your mind. He has no power so he uses deception and lies to try to deceive you.
BethLauren, I am praying for you and your son
When you got saved you received a new spirit. That spirit is perfect and wants to please God. However your mind is not new, you have the same mind you had when you were a sinner. And so God says your mind has to be transformed by reading the Word of God Rom.1 Do not conform to the pattern of this world, but be transformed by the renewing of your mind. (with the Word of God).