It's heavenly for me being in bed (5)
I believe the answer is:
comet
'it's heavenly' is the definition.
I can't tell whether this definition defines the answer.
'me being in bed' is the wordplay.
'being in' indicates putting letters inside.
'bed' becomes 'cot' (cot is a type of bed).
'me' placed within 'cot' is 'COMET'.
'for' is the link.
Can you help me to learn more?
(Other definitions for comet that I've seen before include "High-flyer" , "Heavenly visitor" , "bright star" , "It orbits the sun, with bright centre and long tail" , "Orbiting extraterrestrial body" .)