Today is Sunday and I don't feel well because I have been drinking three days in a row: Thursday, Friday and Saturday.
The drinking has stopped, but I can still feel its effect, so present perfect continuous is the appropriate tense to use.
On the other hand, the drinking happened in the past, even if it is a very recent past. So I'm in doubt about which tense to use. I feel that If I use past simple it makes it sound like it has no effect now, it is a past event. Am I correct about this?
Sentence in the question:
"Today is Sunday and I don't feel well because I have been drinking three days in a row: Thursday, Friday and Saturday."
On Sunday, you would say:
"Today is Sunday and I'm not feeling well because I drank three days in a row: Thursday, Friday and Saturday."
I drank can also be: I was drinking for three days in a row.
The present perfect does not apply here.
Present perfect continuous is sometimes used for an action already finished. In such cases the continuity of the activity is emphasized as an explanation of something.
Why are your clothes so wet? - I have been watering the garden.
In your sentence I have been drinking for three days is an explanation for why you don't feel well, so its better you use present perfect continuous.
