Yeah it sounds like you're lactose intolerant, especially if you're continuing to consume milk products. There's tons out there and lactase sugars get used in tons of stuff.
Probiotics I think will help you to build a new "gut base" after some diet changes and lifestyle alterations but aren't going to help directly with your problem. Check out Labdoor here for supplements- they're independent testers and show their methods so you know what you're getting.
https://labdoor.com/
Forgive me if this has been repeated I did not read all of the responses. I have some experience with probiotics due to having ulcerative colitis for 12 years. Unfortunately, the only thing that really worked was prednisone which is obviously bad for you. So that's why I'm sitting here now waiting for my second surgery. However there was times when probiotics would help relieve some of my symptoms to the point where I could at least function throughout the day. I was told by several Gastro doctors and after using the product myself that " VSL3" is considered one of the better products. Almost any pharmacy should Carry it. Note also that this product must stay refrigerated. It is also rather pricey. Your better probiotics all must stay refrigerated in order to keep the bacteria from dying.
One other probiotic that works and I recommend is "Bragg organic raw unfiltered apple cider vinegar". You take this with water typically teaspoon with 8 ounces of water. Does not taste that great but you do get used to it. I typically would drink it all right before my meal. If you could stand it a little stronger just take a teaspoon with 4 ounces of water and chug it down quickly. You should do this three times a day before each meal. But when you start out just try once per day until you get used to it. Do not take this straight you must mix it with water or some juice if you don't have mind having vinegary juice. I recommend just using water
Please remember that everyone is different and these products will work differently or not at all for some people. I would also recommend if you have not already done so to have a colonoscopy to ensure that you do not have some other underlying issue causing the gas.
Edit: I forgot to mention that Braggs" will actually help lower your bad cholesterol slightly. I didn't really believe this until I I saw the reduction myself.
Edit2: "Floragen" is another refrigerated probiotic recommended by the pharmacist as being as affective as VSL3 but less expensive . However, I never got a chance to try this myself for a long enough period of time to give an opinion on it.