Dextromethorphan is definitely addictive, and dangerous.. "when exceeding label-specified maximum dosages, dextromethorphan acts as a dissociative hallucinogen" (source). This is not a good thing for someone struggling with mood.

It might be very valuable for you to just sort of dry out from these things for a while, to see how you feel without any of it. At least then you can work on things from a truer starting point. You as you; not you+ephedrine, or you+dextromethorphan. These things can stay in our body for a while, and can affect us in ways which our initial experiences with them do not always imply.

And I'm not judging. I understand where the drive to self-medicate comes from. But if you keep going from one dangerous substance to another, it can ultimately be very de-stabilizing.