In future, make sure you shoot your shots as safely and as cleanly as possible, and try not to miss again by making sure you're in the vein the whole way through (as hard as that may be for you; how are your veins?). My principal advice for now would be to get to a doctor, if possible. However, if you can't or don't want to do that, then you can do it yourself, but a doctor can do a clean, thorough job of it, and make sure the abscess doesn't resurface due to retained liquid or anything (another aspect I was lucky on). I understand if this is not an option though (we all know junkie stigma here), so follow my advice above if this is the case. If the abscess gets worse, won't drain, or you begin to feel ill, I'm afraid you need to get to the hospital, as you could possibly have a life-threatening bacterial infection. Do not mess around if you feel any of these symptoms, as you could likely end up losing a limb or dying. I can't stress that point hard enough. I don't mean to scare you, but you need to know the facts, and it would be absurd for you to die over something so petty and (more importantly) avoidable.
Then, we get a peek inside another stomach, this time a human one. Mary returns, with help from writer Fred Kaufman , to tell the improbable story of Dr. William Beaumont and hunter-turned-living-science-experiment Alexis St. Martin. In 1822, an accidental shooting left St. Martin with a hole in his gut that wouldn't heal, but didn't kill him either. Instead, the opening gave Dr. Beaumont a one-of-a-kind window into the human body. And the strange relationship that developed between doctor and patient changed the way we understand digestion.