Sorry, you did not understand the concept of impulse response.
You have a virtual amp as a VST instrument. This sounds terrific in the DAW because there is nothing like the emulated speaker (cabinet) behind it.
Impulse responses are emulated speakers or speaker cabinets. You can combine amp VSTs and speaker impulse responses. It makes no sense to have a whole amp including speakers emulated. If so, you don’t have the possibility to adjust volume, tone, reverb on the impulse response amp. An impulse response is a simple file without any optical means like knobs.

http://www.ultimatemetal.com/forum/backline/947395-best-impulses-since-s-preshigh-theyre-free.html

I only use Catharsis Studio, because they are very well done and few to choose from (less time loss).

When you stack impulses, different mics and such, you are just simply loosing your time. It is a good thing to learn in the studio, but not on DI track or reamp.
Take only few GOOD impulses already stacked for you (no phase troubles, no freq gaps, dry ambiance…) and the only thing you need after them is just EQ.
IR are linear, so everything is just frequency mask over time with ambiance. Nebula “impulses” and real mics are a different animal, because there is dynamic interaction, not just freq “masking”.
My conclusion : you just need Catharsis and EQ (may be some additional reverb for ambiance). Or Nebula cabs, for me ;)
I already erased all my other impulses until i find another single pack to replace Catharsis…but not happened for years.