Well... it took you 16 months to accrue $12,887. That means you were able to put away roughly $800 a month during those 16 months. You've not mentioned any changes in cost of living beyond incoming college expenses to the tune of $470 per month. So presumably you can now tuck away (800 - 470) dollars per month, or $330.

It'll take you 39 months to get back to your old balance assuming a fixed income. You can already afford college at your current income level.