You're all alone. The answer, of course, is simple. You begin Post-Production. Post-Production, somehow, is the part of this process that intimidates people most. Remember, it is not difficult.
Production is massively difficult.
Post-Production is not, as long as you take it step by step. All you need to know about Post-production and finishing your film is the thirteen steps listed below. Just take them one at a time, in the order they appear. There will be no eighteen hour days. Your function will be to hire people and oversee them by dropping in for a half hour here and there.