Hi there ~
I understand your concerns. The redness
in the injection site is due to infection and inflammation. I believe that you are having this problem for a long time and you probably have ended up with cellulitis
which is again an infection of the skin, however it involves a larger area. I advise you to consult a local doctor and also a psychiatrist
to be able to get help in going off of the substances as soon as possible.
I hope this helps. Take care and have a lovely day!