I say, use disinfecting alcohol on the blade. Or maybe soap and water and then rubbing alcohol on the blade. you know, clean it twice or something. I'm not going to comment really on your self injury. I'm not a hypocrite, I have my history with self harm. However, I commend you on the fact that 1)you're going to get help and 2) you care enough to not want to get infected. No judgement and Be careful.
P.S: you are NOT an "attention troll". if you were, you would let yourself get infected so you would have to get treated. Again, Be careful please..ooh also, disinfect your arm afterwards. Just for precautionary measures.