You’re 6 years in. You’re set, by the next time you’re hiring, any company you want to work for won’t even notice that you don’t include a school on your resume.
I say this as a fellow engineer without a college degree.
I feel like it isn't a problem now, question is if it's likely to ever become an issue later on (e.g. a sudden shift in the market to not recruit without a degree that would effect even experienced developers). I may just be paranoid in thinking about this.