I got diarhea about 1hour and 20 minutes right after taking a 2g dose of azithromycin, do i need to retake it?

Azithromycin: No, but you probably would benefit from switching to a different antibiotic.

Probably not, yet: impossible to know, unlikely to have excreted the majority of the dose. Best wait about 3 days to see response to the antibiotic. While azithromycin has far lower incidence of GI problems than erythromicin, it does happen & I routinely advise people to take ~1/4 dose ~every 2 hrs first day, in case they have GI problems, can slow down. A big dose, day 1, usually does work better for infections.

Azithrmycin: this antibiotic often causes diarrhea but it has been absorbed by your system prior to this so you do not need to retake the antibiotic

No, don't retake: Diarrhea occurs in 4 to 9% of patients who take azithromycin. Because this is a common side effect, you do not need to retake the medication. However, do contact your doctor if the diarrhea continues or worsens.

Assuming you need it: (it was prescribed to you, not obtained over the counter) and more than one dose was prescribed, you should continue to take it or consult the prescribing doctor. However, this is a rather large dose. Usual dose is much less, about 500 mg. So question why you were told to take such a large dose initially? Diarrhea can be a side effect.