I know you said you changed the fuel filters a very short time ago, but the fact it won't pull past 2500 RPM and lacking power points to fuel starvation. Is it possible you've got biocrud in your fuel tank? Have a look at the prefilter.

The main way I can tell when I need to change my main fuel filter is if my car will not pull all the way to ~5000 RPM. Guaranteed tell-tale for the fuel filter.

Check also for bubbles in the plastic fuel lines. If you can not see through the lines, it's time to change them, or at least do the O rings. Although your car has very few miles, age kills the O rings and air can get in.

Or perhaps air starvation? Changed the air filter lately?

Rgds,
Chris W.
'95 E300D 326K