Magnesium ox pill got stuck. Think dissolved in throat after a day cuz it feels different then when was first stuck now throat mildly burning/irritated

Inflammation. Always swallow pills with enough water, sitting up. Some meds can "burn a hole" through the lining of the esophagus if they don't pass into the stomach; can cause very painful ulceration. Don't know if that is what you have. Call your md; meds available to speed healing, if that is what is going on.
Not to worry. This is common and would just allow to heal. It is probably just a contact reaction to the pill that was there on the tissue of the throat. Drink lots of water etc and keep an eye on this. As long as this gets better each day nothing to worry about. You can take a tylenol (acetaminophen) or advil and this might help some of the discomfort also.