I had similar problem with sus but no redness. sore as hell for at least 7 days. worse i've ever had from sus. Try massaging, heat pad, and arnica gel. i have got my soreness down to a day or two . Thanks to this site. I heat up syringe with heat gun then inject.Then I put a hot wet towel immediately on injection site for a couple of minutes. When the sorenesss starts to kick in a day later I'll massage it and put some arnica gel on soreness before sleep. I normally do this for two days. soreness is gone after two days. Hope this helps in future injections.