Hi and welcome - sorry your first post has to be a distress call!
The first thing I would say is take the engine cover off and take a look to see if you've got any oil around the coil pack on cylinder 1 if you've just recently changed the oil.
This is pretty common as if you slop a little bit when filling (which unless you used a funnel you will) the design and angle of the engine makes it run into the spark plug holes on cylinder 1 which causes all sorts of misery. If it looks oily down there remove the coil pack and clean it out.
The MAF is probably not likely to be your problem - do you still have the engine light on?
Unplug your MAF and go for a drive, it will idle rough as hell once up to temperature and off choke, maybe even stall, but should run much better if your MAF is at error.
If it does run better with the MAF unplugged I'd like you to have a look at the rubber hoses between the airbox and the MAF and the MAF and the throttle body, to see if you've got a leak rather than the actual MAF itself.
I would also highly recommend getting yourself a diagnostic cable if you have a laptop - you can get free software that will read the fault codes for you - if you haven't already as knowning the fault code you've got would be very helpful.
1999 156 1.8TS Sport Pack 3
2001 166 3.0 V6 24V Super
2003 156 GTA 3.2 V6 24V
2005 156 1.9 JTDM-Jet Sport
2008 159 1.9 JTDM Lusso
1997 GTV 2.0TS Lusso
2001 147 1.6TS Lusso