Dreadful experience on different drug for morning or evening, perhaps (5,5)
I believe the answer is:
Here is my best explanation:
'morning or evening perhaps' is the definition.
'dreadful experience on different drug' is the subsidiary indication.
'dreadful experience' becomes 'hell'.
'on' says to put letters next to each other.
'different' becomes 'other' ('other' can be similar in meaning to 'different').
'drug' becomes 'e' (e is another name for ecstasy).
'for' is the link.
(Another definition for hello there that I've seen is "Hi!".)