How do you know nothing was coming out?
You realize that less than 1% of women worldwide can't breastfeed, right?
If the softspot on his head was sunken in and he had stopped producing wet diapers, then he was malnourished. Otherwise, you were paranoid.
Did you consult with a lactation specialist? How about LLL? Did you try oatmeal, tea and fenugreek? How about Relegan (sp?) Assuming that you really did have a diminished supply, did you use a supplimental nursing system so that whatever milk you produced went directly to your child while they were being supplimented with formula?
Or did you assume you were not making enough, fed formula in a bottle because you didn't know what else to do and then assumed that your children didn't want your breast after that?
You can still breastfeed even if you have to give formula. If you want to breastfeed you shouldn't give bottles because it causes nipple confusion. If you have low supply issues, you need to nurse MORE and not bottle feed. If your kid is malnourished you know because their temples, eyes and soft-spots sink in and they are lethargic and don't urinate... you can boost your supply with an SNS.
There is probably no reason at all why you couldn't have breastfed. It's hard sometimes... but if you had really wanted to, you could have.