sputtering/jerking 93 dynasty

sorry, i'm a bit of a noob here, and not much of a smart guy when it comes to cars, but just seeking some advice from those of you smarter than I. :) first off, 1993 dodge dynasty, it's the 3.3L engine, 143K miles on it, and been relatively troublefree; especially for an older car.

in the past, i've had shaking problems at stops, but it'd 'catch' and right itself and all would be well. about 3 weeks ago it got worse...once i put it into gear, it feels sputtery and almost like a hesitation. it's stalled on me 2 times on the freeway. when i get into high gears there isn't much acceleration, and whenever i stop, my oil pressure drops and the car jerks and sputters, but now never rights itself.

i've tried the Heet additive hoping it was just moisture, barely any noticeable improvement...tried the fuel cleaners and all that as well...no luck. I've never replaced my fuel filter and my uncle (via a phone diagnosis) seems to think I should start there. does that sound right? any other info required that may help anyone get a better idea? i'm most likely going to have to go into a shop for the work as I have no garage and no idea what I'd be doing.