should i inject waterbased into shouder

i started doing a with this stuff calle suspina, its125mg of test suspension mixed with 25 mg of tren. i was putting it into my shoulder and after 2 weeks my shoulder swelled up and got so infected, what went wrong
Dirty gear possibly.. also water based injections tend to be pretty damn painful.. I do believe someone has made a oil bases suspension...but I'm not sure who....