Yeah, +1 Ethan. It is either your head gasket or a cooling system component. Here is the list of things you could replace, in case you aren't familiar with that system:
1) Water Pump
2) Radiator
3) Heater Core
4) Upper Radiator Hose
5) Lower Radiator Hose
6) Heater hose head to valve
7) Heater Hose Valve to Firewall
8) Firewall to block
9) Use new OEM Honda clamps on hoses
10) unlikely but possible, small hoses from block to intake manifold idle controls and back
There is a quantitative maximum number of things to do. If it were me, and I wasn't familiar enough with these components to know what they were, I would pay someone to do a standard cooling system pressure test. If you want to fix this thing yourself, PM me and I will explain in painful detail step by step what to do to avoid unnecessary cost and still root it out. I agree with everyone though, run it up to temperature, drive it hard even, then bring it home and park over a bunch of cardboard. Leave it running for a minute, then turn it off. Check it out after like 10 minutes and see if there is so much as a drop from anywhere. If it's dry, and you've added and added coolant, and burped the system and everything, then I'd get a compression test and a cooling system pressure test done for sure. Again, if you want to DIY it, just let me know.