Sorry about your tough start this time round. It's great you're still determined to breastfeed.
I feel I should start by telling you that you
can actually have antibiotics that are able to be taken while nursing. It is important because plenty of women do have post-partum infection and need to be able to breastfeed. I hope you don't mind me telling you this
Antibiotics safe to take during lactation are listed and discussed in detail on this link (I'm sorry if it's too late to change what happened to you but someone else can benefit or you'll know in the future).
http://www.breastfeedingnetwork.org.uk/supporterline/antibiotics.phpA doctor called Thomas Hale is one of the world's experts on breastfeeding and medication and if you ever find yourself in the same situation check out his website forum and discuss it with your doctor (who perhaps could do with a little education, dare I say?).
http://66.230.33.248/cgi-bin/discus/discus.cgi?pg=topics&access=guesthttp://neonatal.ama.ttuhsc.edu/lact/It sounds to me as though you really need to talk to a lactation consultant. Talking to an expert need not mean big money (although in fact a fee for an LC visit is a small proportion of the cost of a year's worth of formula). There are free helplines and the La Leche League is available in almost every country worldwide. A LLL leader could check your baby's latch and talk to you about building up your supply perhaps by using a pumping regime while breastfeeding on demand or taking a supplement. Canada has some pretty good resources - Dr Jack Newman is based there and he is
the breastfeeding guru (but if you're called Pinemom am I'm right to guess you're not exactly in Toronto?).
Wet nappies sound good so obviously he is getting something but you may need more advice about further developing your supply after your rocky start. Good Luck.