I have stomach ache everytime I drink milk. I've tried lactaid but that didn't help. Carnation helps me but I want to have milk with cereal. Please help!?

Alternatives. Lactase deficiency (intolerance to lactose/milk sugar) can lead to symptoms you describe; if no response to lactaid (lactase), you could try a milk substitute (eg. Soy milk, rice milk, almond milk). Some of them are quite good. Some people (eg after gall bladder removed) have problems with fat in the diet, and whole milk contains quite a bit of fat. Trying a low fat/non fat milk can help this.
Consider. Consider soy or almond milk as long as no know allergies. Also consider the cereal if this is when symptoms develop.
Digestive enzymes. If you take digestive enzymes prior to taking milk products will help break this down easy - the enzyme should have protease, lipase, amylase, lactase.
Try cow alternative. Lactose intolerance is very common, particularly certain ethnicities. Stomache ache is not typical sx: more often bloating, cramps, diarrhea, flatulence. Also, if the ache occurs just after drinking, it is likely not li. Perhaps the milk is too cold. Other causes can be celiac spruce, certain bacteria in the gut, gastritis. May try smaller amts, or soy milk, goats milk, or yogurt, buttermilk...