Hey Ty and harddtime,
I'm not the one with the abcess, so it's easy for me to talk. But all this stuff is a measured risk in a variety of different ways, from buying to injecting to different health risks. Before I started this, I made a list of every nasty thing that could happen to me and how I would try to deal with it. Made me feel a little better about it because I never want to get caught with my pants down.
So as far as injecting goes, just take every precaution you can, then stick it! Check the vial for shit, wipe the top, wipe the spot, then jab it. Just be prepared to go to the doc if you have to.