How do I relieve bloating and gas, even though I only drink lactose free milk now?

Gas. Many processed foods contain dairy products; so you have to check ingredients. Of course, other dairy products contain lactose, too—cheese, ice cream, yogurt. You can take lactase tablets (otc) before a meal to help break down lactose. Simethicone can help break up gas bubbles to relieve bloating & discomfort.
Food diary/read. Most gas is created by germs in your gut as they digest food your body does not. Common triggers include the lactose you are dealing with & complex sugars in many vegetables. You may need to keep a food diary to discover which ones make you gassy. You can take enzymes that help. Lactaid helps with lactose and Beano is a product that helps with vegetable sugars. Read labels to avoid random exposure.