There are two sources of the symptoms associated with lactose intolerance.
Undigested lactose changes the molality of the intestines, which means in English that instead of water being absorbed into the body from the intestines, water is actually drawn into the intestines. This naturally helps create diarrhea.
And undigested lactose can also be fermented by certain types of bacteria that naturally live in the colon. The fermenting creates gases and fatty acids. These produce the bloating, cramps, and flatulence that are associated with LI. Which sounds like what the OP suffers from.
Different people are affected by these pathways in different ways. There’s nothing you can do about molality except to remember to take lactase pills with dairy products.
You can change the composition of the intestinal flora, however, to a variety of “good” bacteria that will themselves digest lactose. This is an example of probiotics.
Yogurt with live and active cultures have exactly these good bacteria. You can, therefore, try to eat yogurt regularly to see if you can use the good to drive out the bad. Massive quantities are not called for or even desirable. (You are not exposing yourself to the lactase enzyme, but to the lactose itself.) Start with a cup of plain yogurt (as little extra sugar and junk in it as you can stand) a day.
You can also buy probiotic pills that claim to do the same thing. Major brands advertised to the LI community are Digestive Advantage and Lactagen. I’ve never tried either, so I can’t recommend one.
Although Lactagen especially likes to tout itself as a “cure,” this treatment will only work as long as nothing upsets the compositon of the bacteria in your colon. A dose of antibiotics will kill them all off, good and bad. Mild food poisoning can be a problem. Travel oftens upsets the balance by introducing new species in. Even drinking new sources of water can do it. Your insides are delicate.
Personally, I think lactase pills are fantastic. I never leave the house without some in my pocket. However, if you don’t want to have to remember them this is something that is proven to work for the majority of people with LI.