Make sure you are absolutely confident about how much your are doing. you might want to try doing it with a friend present in case of emergency, cuz it doesnt seem like your have much of an opiate tolerance. i dont think what you shoot before was very good or even dope, cuz regardless of how much youve snorted, the first time you inject, its gonna blow you away even if its mediocre dope. make sure you push the shot in very, very slowly. you should even take up to like 45 seconds pushing it in. if you start to feel that its hitting you too hard, stop feeding it into your vein and wait. if you choose to do it by yourself, have 911 dial in your phone and press send and try to say as much as you can about your location if you feel yourself falling out. use sterile water. if you cant find sterile water used distilled water, you can buy it at the store. always inject with needle pointing towards your torso, always have the needle hole facing upward to minimize vein damage. make sure you filter your dope with a cotton and not a cigarette filter, and use about 60 units of water, this will aid you in pushing the shot in slowly. sver, very slowly. if you starting to feel super light headed beyond just the high, stop IMMEDIATEly! the act of injection itself is not inherently dangerous, the danger is gauging the dose. later you can afford to be a little more confident, but even though you know how snorting a certain dose affects you, yo u have no idea how an IV dose will. be careful. there are lots of safe injection guides on internet read one of them too