You`re experiencing what`s known as mission creep. The pressure of events shifts your goal and all the earlier calculations no longer add up. The details that you just finished nailing down are hanging oddly in space. Backtracking and reverse engineering feel like a waste of time, but your other reasonable options are few. Take yourself away from all this, even if it`s just for a short time. Talk or visit with a member of your family as a means of anchoring yourself. Someone who has known you for a long time will be happy to help you figure out what`s what.