having battery drain issues

Assuming you had the meter's switch in the right position for the 10A input jack that would be a reading in amps, so the 0.38 you measured is 380 mA, similar to having an instrument panel lighting bulb turned on. Not a huge amount, but it's still too much. While usually the goal is to keep it more around 20 mA, I would have expected your drain to be even higher than the 380mA if it drained your battery in only two days. Do you still hear the relays clicking when you connect and disconnect them? If you can get to them, maybe try pulling all the relays you added out from the sockets to see if it drops the drain. Though it may be harder than just pulling the fuse, if you pull out the whole relay, it opens all possible drain paths through the relay coils and also the contacts, so you can be sure it's not the cause.