Stinky farts and no poop

I'm a ftm of a 2 month old. He doesn't poop regularly since he has been a month . It's been three days since he pooped, be is very unsettled, cries often, not sleeping and his farts are proper stinky.

I am EBF. Don't know what I am doing wrong cause I heard breast fed poop everyday.

I have been to doctor they say it's a phase which shall pass.

Is it normal?

What can I eat to help him be regular?