Huffing anf Puffing 94 Nissan

Hi,

My lovely 94 Nissan Sentra has a problem of shaking and sounds like choking when still. As soon as I drive off and step on the gas, it chokes some more almost like it’s about to misfire. This happened after my mechanic changed the air filter. He thought it was the idle that needed some adjustment. but after a brief improvement, it’s gotten to its shaking/choking state. Any suggestions? Thanks