Night weaning at 18 months is very achievable, but stopping the feed suddenly rarely works when a child is this attached to it. Gradual, consistent change over one to two weeks usually goes better than removing it outright.
Next Steps
Shorten the feed a little each night instead of stopping it cold, and follow it with the same comfort steps (carrying, patting, water) so he links those to settling too. If someone else can take over the settling for a few nights, he stops expecting the feed specifically from you.
Health Tips
Expect a few rough nights before it gets easier, so try not to switch approaches too often. If it still feels unmanageable after a couple of weeks of consistent effort, your pediatrician can help with a more structured plan.