Salaam - Reconsidering Faith After Leaving Islam

Assalamu alaikum - I’ve been away from Islam for a few years because I came to believe there’s no God. The idea that a Creator would punish people forever, especially for simply not believing, felt cruel to me and unworthy of worship. I also had moral objections to some Islamic rulings that seemed unjust. Lately I’ve been waking from terrible nightmares about hell. When I first left, those fears were constant but eventually faded. Now they’ve returned, and I’m honestly questioning whether I made the right choice. I’m trying to look at this without bias again and would appreciate points or perspectives that might show Islam is true. I also have specific concerns I’d like help thinking through: - The claim that Islam is “timeless.” A lot of classical rulings were formed in 7th-century Arabian society and don’t seem to fit modern, pluralistic contexts. - Slavery: instead of a clear abolition, the texts set many rules about how to treat slaves, whereas things like alcohol were prohibited outright once they were seen as harmful. - Child marriage: I know the usual explanation points to historical norms and markers like puberty, and that many societies did similar things. Still, it seems dangerous and ill-advised, so why would Prophet Muhammad, described as the most moral of people, endorse something that appears harmful or scandalous? If anyone can offer thoughtful, grounded responses or readings that address these points - especially from a Muslim perspective that engages with history and ethics - I’d appreciate it. Jazakum Allah khair for any help.