S.H.
It seems out of the ordinary that only in the past 2 weeks... hes has been crying every night before bed and seems afraid to be alone and will need to sleep with his little brother in his bed.
Have you asked him, why and what is scaring him?
Did anything happen to him, or anywhere?
Is he having bad dreams?
Did anything change in his life?
Did someone tell him anything negative?
Did he perhaps overheard someone say anything?
Was he ever alone somewhere that he got scared?
Is there something about "his" particular bed, that is scary and bothering him? And perhaps that is why he "can" fall asleep in his brother's bed?
Could it be he is afraid of heights?
I think, he needs help in working it out. Not just leaving him be to wallow in it.
Something is clearly bothering him.... and he needs comforting or help in "explaining" what is bothering him. Maybe he just does not know how to explain it.
All the best,
Susan