Yeah, DXM has a pretty tremendous hangover... it has lingered somewhat for two days for me before but usually it lasts all the next day. It can have some subtle effects for longer. But don't worry about it because that will make you feel worse... rest assured you will be fine. Just don't do it again if you had that sort of reaction. And if you don't feel like doing any drugs again, then more power to you... they can be rewarding but they can also easily lead to bad places. However, if you do feel like trying some other things, you shouldn't feel like they'll all be like DXM because DXM is a dirty, shitty drug. In my opinion.
What DXM product was it?