Now you've felt it for yourself, it's not scaremoarning, it's not people telling horror stories, no, it's the raw truth: IV coke is among the most dangerous things that you can do with drugs.
The obvious advise is stop injecting cocaine. This drug is super compulsive; with other drugs you can follow some danger reduction rules, like dosing it conservatively, wait enough time before redosing and so on.... IV coke nature is just maniac and it will oush you to do shot after shot, increasing dosages to chase that extreme bellringer feeling and being safe at the same time. It just don't work like that.
If you will keep IVing coke, get at least some clonazepam or even better diazepam and take it 20 minutes before shooting. Get also some more benzos for the horrible comedown that will be waiting for you to finish your binge.
Safe fent/zenes free opiates are also a goog tool for the comedown, but don't you mix opis and benzos during a IV cocaine binge, cause coke fades away soon, and then the mix of downers will hit hard, and maybe you just avoided a coke OD just to fall into a benzo&opis one.