No. Just no. This is your jugular vein, likely external but could be internal.
If you miss - you could hit carotid artery and die. Bleed out (do NOT want to bleed from carotid, will kill) or vessel will spasm and cause a massive stroke. You could hit nerves and paralyse your neck and below. You get abscess in neck. This could destroy your carotid artery and kill you. Or jugular and kill you. Or erode into your windpipe and kill you, or any one of the vital nerves/muscles there. You could hit the top of your lung (extends above collar bone) and collapse your lung. This can kill you too if you don't get treatment and it is severe enough, and I imagine you don't have any reserves left really to fight becoming seriously ill.
If you shoot a dirty shot, you can get serious consequences. If you cause a clot, you can get a stroke. If you nick it, you could bleed out. There is a reason doctors do it under ultrasound guidance in full theatre clothing, in sterile conditions. You really really do not want to fuck this up. To paraphrase Tripman, you can't have a head amputation if it goes wrong can you?
In hospitals, jugular injection is done under sterile technique like an operation. It is a major procedure.
If you have reached this stage - dude, please reassess your IV use. Believe me I know it is not that simple. But this is the last straw when all else has been exhausted, and I am worried it is only a short walk to the morgue from here. Try rehab, methadone/bupe/plugging, whatever works but do not inject into your neck
