First of all, probably forget what is 'normal.' If you've made it to your 30s, I'd hope you weren't so obsessed with what other people are doing and comparing it to what you need to do with regard to how your relationship progresses. I'm sorry but your obsession about a ring sounds incredibly immature.
Big surprise proposals where there's a ring already picked out and whatever you're seeing on social media etc, that's not normal and I feel really badly for the few men who have been pressured into a whole performance they weren't comfortable with.
Far more common (since you've used the word 'normal') is a discussion about marriage and what you both want out of life re: kids, your families, religion if it's a factor, finances etc. More often than not, it's more of a "we should get married" "yes, we should!" type exchange, and once you've realised that's the engagement happening, you start talking about dates and rings.
I will go against some of the grain here though and say 18 months is entirely sufficient for many people; DH and I married after knowing each other 10 months, though we had the added pressure of being different nationalities and needing paperwork to stay together. We've been married 20 years now. Sometimes you just know.
You aren't unreasonable to have a timeline, but he is also not unreasonable for not being ready for your timeline and ring demands. If you're still interested in him, I think you need to have a frank conversation. Less ring focused, more actual marriage focused.