This is going overboard. There isn't that much context to come to these conclusions.

It's OK to want a ring and keep things traditional if that's what OP wants. They have clearly worked through a lot together and just because he's has commitment issues doesn't mean OP should sacrifice her wants a desires either.

A lot of couples choose rings together and making the suggestion shouldn't be that offensive. And partner's each have different values and expectations.

For example, I didn't want a diamond so my partner got me a $200 gem ring. It was perfect and he knew what I wanted. My Dad however, got my Mum a ring that had a dolphin engraved on it that was jumping towards a star. I saw it and we both had a giggle years later but she was devastated at the time and guess what, they didn't communicate their needs.

I agree that they need to talk through this but it sounds like OP has tried that and he's blaming her for all of it and potentially shut off. Hard to say though with the available info.