I have worked on many Honda's Not an expert by any means but
I would venture to guess that your head gasket is blown. These cars are famous for having blown head gaskets and I have replaced many. Most at 200k miles or above. (One at 110k) Open radiator fill to top and look for bubbles. Compression leaking into water jacket and forcing out coolant. Changed my 4th one last week.
Pressure test would help.
Thursday, January 28th, 2021 AT 9:34 AM