Then he has countered your PAK43. You can minimize it's effects by making a halftrack to reinforce the PAK43 , repair the PAK43 in between barrages and by not keeping units clumped up around the PAK43.
The PAK43 needs to have counters, otherwise you could just make a PAK43, park a hull-down Ostwind next to it and be safe from nearly everything.
Ofc that every unit needs to have a counter, Pak43 is just... not that good.
It should work like bunker, so it cant be decrewed. So it can last a hit or two more from some type of artillery.
I would still rather take falk88 from vcoh, easly killed by everything that isnt armor, but small target size, doesn't take alot of space, long range, cant shoot trough buildings.
More practical than this unit.