Stalling, P0101, Vacum boost playing

I have a 1999 x308 4.0 v8 NA

After 20 min drive, it was needing to rev higher to change gears… seemed to lean

Then after 30 min , i stopped with the car, on restart it barely started and twice died/stalled
was able to get home, I initlally thought maybe it was old fuel, so i filled it up with fresh fuel, but same problems later on in day, was rough, but for 90% of the time it was smooth.
It Hesitates with throttle initially ,wants to die, then all ok on freeway.

OBD2 said P0101… this is MAF sensor (ARF Air Flow ratio)
in real time OBD2 data i noticed it tried to stall again, by itself with no throttle and "Vacum /Boost " measure went from +4 to -18 Hg, and air fuel ratio played up and down.

So is this a Vacum problem causing AFR P0101 error, or other way around?

I Will clean MAF sensor but it is 2 years old… I cant see how MAF problem would make Vacum/Boost swing so much with no throttle. correct me if im wrong.

So Where would such a large Vacum leak reside to cause it to stall??

Best regards
Sydney Australia