Transmission filter

Driving home from work my tranny seemed to be struggling to change. Started with a little jerking then had a hard time getting up to even 45mph. Fluid level is fine. Got a new filter but am having a hard time getting to the bolts on the pan near the crossmember. Any ideas? Vehicle is a 1996 Chevy Blazer LT with 4X4. Is there anything else that it could be other than the filter?

Undo the trans mount and raise trans or see if crossmember will unbolt and slide back out of road.
A new filter and fluid is a good start.
If that does not help check for codes on trans and engine PCM.
Is the engine running up to par?
MT