Anyone has times like this....you know how to do it but can’t!

I work in construction which requires me to do AIA forms. Which are basically application for payment that includes contract amount, retainage, and balance left to finish. I had the month of December off so my boss took over for that month. NOW I haven’t done one in a month and have to go off of where he left off and let me tell you..ugh. I can’t figure out where he got one number, I asked and he explained the whole form but not that number lol then got interrupted by calls which led to him leaving the office. I am so mentally frustrated at myself for not figuring it out..I have I have been binge snacking ever since I look like I’m going crazy this is how I feel...😩😂