‘Good’ vs ‘Well’
This is one of the simple mistakes that can distinguish English learners from fluent speakers. Generally, ‘good’ is an adjective; it describes a thing (good meal, good worker, or good feeling!). ‘Well’ is usually an adverb; it describes an action (to play well, to sleep well, to feel well!).
HOWEVER, ‘well’ is also an adjective when talking about health!
Thinking in English 