Minor QoL PSA: if you get indigestion every time you consume milk or milk products, you probably have lactose intolerance, which can be fixed semi-cheaply and effectively by taking a lactase supplement before consuming milk. Lactose intolerance is widespread in adults (statistics range from 33% to 75%). Lactase supplements are available without a prescription. Considering how useful as a source of nutrients, not to mention tasty, milk is ..
It could be also be casein intolerance. I actually feel fairly okay when I drink milk, but consuming a casein protein powder makes me bloated.
P/S/A: There are single sentences which can create life-changing amounts of difference.