The $7,000 is already wasted. Don't focus on that, except to make a commitment to your son that you won't waste his future education.
Compound Savings Calculator
Thinking of your son for a minute, you could easily calculate the education fund that you will amass by setting aside, say $1,186 per year, (pack a day rates) which will be $47,969 accumulated for his college education by the time he's 18. He'll be so proud of you.
If you contribute to a tax deferred education savings or retirement savings plan the accumulation for him is even more.
It's awesome that you've got a young boy who will grow up trying to be just like you. You've got the best motivation in the world to quit smoking. You've got something to live for.