Its not in your mind.
I got sust flu before I even knew it existed. After injecting a couple shots, 1 every 5 days, I came down with a fever and felt like shit.
I didn't know what it was, it only lasted a few days, so when I hit my next shot it happened again.
Someone needs to give an explanation as to why some people get this. Here is mine:
Sust often causes inflamation of the site for many people. While the body is fighting this inflamation and foreign substance loaded with alcohol, your immune system puts your body in a flu like state. Its really a fever.
The inflamation can turn into cellutitus or even an abscess.