Is the injection site warm? if it's not warm its probally just irritation. If it is warm it could be an infection, not to scare you bro but remember its your 1st jab so its a virgin muscle aswell, if it gets hot then u need to see a doc
winny would not burn fat only a good diet and exercise will
you say you have a slow metabolism? haven't you looked into certain food/drinks that can speed it up?
try reducing calories and carbs and upping your protein and hit the cardio hard
I managed to lose 7lbs just be changing my diet...