If you decide this is what you want, then go for it- today, now. You have selected one of the most competitive job fields in the world. The only way to succeed is to strive to be the best, and it needs to be approached with the same mindset found in world-class athletes. Seek to improve yourself constantly, by an inch or a millisecond everyday, and you will succeed.
Formal education can help, but never let this prevent you from gaining practical, real experience as soon as possible. Join mod/indie teams and constantly seek feedback from everyone and anyone. Those who grow the most, are those who receive the most feedback.
Here are some communities that might help you get started on a mod/indie project or give you advice on your discipline:
We wish you the best of luck in your efforts,
Torn Banner Studios