Sluggish, shaking, and low rpms in Drive, drives smooth in 1,2nd

[99xlt2wd]

Hi this 99 2wd has always driven real smooth switch from O/D on off overtime never any change. Recently its basically not operating in Drive. Put it in second i can get up to 60mph at sub 3500rpm. In drive cant get the rpms up. Switch at speed to Drive it starts fluttering and gets shake. Could it be the clutch? Fluid is red and clean. Have a new filter but haven't taken it in yet. No codes or lights for Transmission.

 

[AWAR]

Replace the fuel filter first. Then see how it does.