I've been here!! I'm a cap and dated an aquarius for almost two years

honestly the spontaneous thing drove me INSANE at first. but I kind of learned to loosen up a little? like they helped me realize I was being way too rigid about stuff that didn't actually matter

the key for us was communication about what we actually needed. once we figured that out it got so much better

Looking at this combination astrologically, Capricorn and Aquarius are actually neighboring signs which creates an interesting dynamic - you share Saturn as a traditional co-ruler (modern astrology gives Aquarius Uranus, but Saturn is still there).

What you're experiencing makes complete sense. Capricorn is cardinal earth - you want to build, plan, make things real. Aquarius is fixed air - they want to think, connect ideas, stay free to pivot.

The tension you're feeling isn't incompatibility so much as it's two different operating systems. The question worth asking is: do they respect your need for structure even if they don't share it? And can you appreciate their need for space and spontaneity without taking it personally?

When those two things are in place, this pairing can actually be really complementary. Cap grounds the Aquarius ideas, Aquarius helps Cap think bigger picture.