Will probably get down voted or ridiculed. There are many engineers/scientists here how will give the logic ways (divide and conquer, research etc).

But here are some non logical ways: - reframing - ignoring/delaying - accepting - praying - delegating

Or what the stoic/religion used to say

God, grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference.

P.s I ain't religious or superstition but there is some wisdom in those teachings.

Now in the context of a project if you really can't find any solution, then document and communicate your findings until the budget runs out..