I'm sorry you are having a difficult time with feeding your child. Usually switching formulas to your child's specific needs will help reduce the amount of spit up, though small amounts of spitting up is normal.

What did you find out from your doctor? I think it is most likely blood. Stopping breastfeeding and then starting up again later takes a lot of time and patience and sometimes the baby can pop a small capillary which makes things look a little scary, but there's nothing to worry about. It's never a bad thing to get it checked out by the doctor either if you are really worried.

Hope everyone is ok now.