How much "diamorphine" did you take. If it's a little than it might not be dangerous. 25mg of tramadol and .25 of xanax isn't that high of a dose, though if your fucking high as fuck on h it could push it into the danger zone.
Why call it diamorphine? You'd be technically right, but the name diamorphine is usually for prescription heroin, not street H. Also what kind of heroin is it? If you're in Europe, Africa or some parts of Asia it's usually freebase heroin for smoking, not as good to snort. If you're in East Asia, Canada(I think) or the east coast US it's usually heroin hydrochloride. It's good to snort, tend to burn up and be less effective smoked. And if you're west of the Mississippi in the US it's black tar heroin or mud(tar cut into a powder). It can be smoked or snorted.