Is an aspiring PM who struggles with decision making absolutely doomed as they consider pursuing PM?

It's hard for me to think anyone is 'doomed' per se but I would make this a focus area if you are truly trying to get into product management. Making smart decisions quickly is a strong product management trait and so to be successful, you will need to be comforatble doing that. I would probably reverse the lens and ask yourself if you would be happy making smart decisions quickly everyday. Does that excite you? If so, then dive into why you can't or don't want to currently. If it is not exciting, consider what you like about product management and see if you can get that same joy in another role.