Some ladies swear by fenugreek as a supplement as well. I’m a chronic over producer so I don’t typically supplement but I’m a huge advocate of breastfeeding.
I'm so sorry that happened to you. I had a nurse after delivery that was so unsupportive of me breastfeeding. Seeing a lactation consultant after I left the hospital saved me! She helped with latching and positions. I reccommend doing that. I wouldn't worry too much about the colostrum, because it is not a sign if you'll have a good milk supply or not. They say you produce more milk the more baby takes out. Put baby on the breast whenever they want. Don't go by the clock and wait 2hrs or whatever.
Try not to stress about what you can get out. Milk takes 1-4 days to come in usually and babies are way more efficient at getting it out of us than even a hospital grade pump. My staff have always been supportive of my breast feeding and they even have a free lactation visit usually before I leave. Hopefully baby doesn’t need to leave your side and you can prevent any bottles. Just be super clear y’all are going to be EBF and don’t allow paci or bottle in hospital. Additionally a newborn has a stomach the size of a small marble when born so they do not need much to be fed well, we are born with fat to help sustain us until milk comes in and they get the hang of it. Spend tons of time skin to skin and let baby nurse on demand for the first few weeks and you will be good momma! Don’t hesitate to ask for a lc or make appointments with one after you leave the hospital. Look into some lactation cookies/tea to help your milk come in. If you are a fan of beer dark beer can help boost supply