Dirty needle and nursing. Please don't be judgemental.

I am a nurse and was giving a IM injection of steroids to a patient in preterm labor. When I went to engage safety the needle came off the syringe and hit my hand. I immediately smiled and told patient I'd be back to check on her soon. She had no idea this happened. I left room in complete panic, not because of exposure risk to myself but rather I'm breastfeeding my almost 10 month old. Oh my god what have I done. I quickly told my boss and went to the ER for work up. the patient has no significant history or prior drug use. Her labs we all negative at beginning of pregnancy and also the night of the stick. They tested me and everything came back negative. I was told it very low risk but there's a window of time the tests wouldn't show. I stopped breastfeeding with intent to start after 2nd lab draw. I just found out, the window could be three months. I'm at a loss for what to do. I've been using frozen breast milk but he's refused it because it smells and tastes different. He went from eatin 35oz per day to like 15oz. He is also super fussy all the time and refusing sleep. I'm so sad and frustrated that this happened to me. I feel so depressed and disconnected. I feel like I've failed. This wasn't part of the plan.