The thought of shirk as the biggest sin really shakes my faith sometimes

As-salamu alaykum. I'm a pretty new revert, and everywhere I look in learning about Islam, the one sin that's always called unforgiveable is shirk. I get it, Allah (SWT) is super clear about it in the Qur'an. But, living in the West, it’s been hitting me hard lately, especially thinking about faiths like Hinduism. With Christians, Allahu 'alam-they’re people of the book, so maybe there's more nuance. But many Hindus I've met are genuinely peaceful people. They seem to live in harmony with others, not like the aggression described from the time of the Prophet (PBUH). Knowing that such a huge number of people, a whole culture, might not be forgiven on the Day of Judgement just makes me feel sick and scared. It honestly tests my faith more than it strengthens it. Then I think about the really awful stuff happening-like the oppression in Ghazza, or crimes against people. The idea that someone doing those things could still pray and be forgiven, while sincere people of other faiths might not... it's tough to sit with. Any advice or resources that could help me make sense of this would be really appreciated. JazakAllah khayr.