I have clients that get so stressed out when they totally screw up a certain category on their budget – gas, savings, groceries (a big one!), etc.
Trust me when I say this is the norm! The key is to accept it, adjust as needed, move on.
And, if it's because of behavioral concerns (i.e. shiny object syndrome) then develop ways to trick yourself into not letting it happen again. By understanding it, you can tackle it.
Hope this helps!