The best thing in my opinion you can do is breastfeed (and cut dairy from your diet. Breastfeeding is just so important for any child, but even more so for a child that appears to be atopic (allergy prone). Soya is really not a great idea now, I'm surprised it's been prescribed due to the worries phytoestrogens.
http://www.babymilkaction.org/resources/briefi ngs/tessasoya03.html
(Particular bugbear of mine as I was a soya milk baby, ended up with PCOS and disease like crohns, both of which breastfeeding called of prevented)
Formula really was just invented as a last resort, a medical necessity if there really was no breastmilk about, not a choice. It can upset gut flora, many allergies are linked to poor bowel health. Cows milk is a foreign protein, anything foreign that passes a babies lips before 6 months can upset them.
It's not too late to breastfeed. Even women who have adopted babies can induce lactation. Find a good breastfeeding counsellor to help you.
http://www.kellymom.com/bf/supply/relactation. html
It's very rare a woman physically cannot breastfeed (only 2% cannot), the rest is usually poor support and believing myths.