What are Juliet's conflicting emotions before she takes the drink? What causes the great despair of these characters: Lady Capulet, Nurse, Paris?

As she contemplates drinking the potion, Juliet of course wants to drink it so as to be able to be with Romeo.  At the same time, she is afraid of possible bad consequences.  These are:

1. The potion could be a poison to cover up Friar Lawrence's complicity in marrying her to Romeo.


2. She could awake too soon (before Romeo comes) and suffocate.


3. She could be driven crazy by the spirits of her dead ancestors.  She sees herself playing with their bones and eventually bashing her own brain in with "some great kinsman's bone."