During doing an exercise i jumped and landed on the side of my ankle, causing it to roll and now it hurts when i walk, a lot when a roll it and it hurts when i run. it's been hurting for about half a day now?

Sounds like: A sprained ankle. Usually in the acute setting, within the first week or so of an injury like this, "RICE" (rest, ice, compression and ankle elevation are utilized) and activity modifiction to minimize too much weight bearing. Sometimes people will use a stirrup based aircast to help stabilize the ankle. If you can't bear weight on the foot or have severe pain then seek an inperson evaluation.