First, see a qualified urologist, to determine if there is any organic cause. If there isn't, then use the various techniques out there to retrain your body. Sometimes, some forms of sleep apnea can have symptoms including inability to wake to urinate. You may, after getting checked out by a urologist, need to go into a sleep lab to determine further causes and treatments. IT may be a symptom of something more serious, or simply that you are a very deep sleeper who needs to retrain your body and subconscience. Regardless, at 28, you need some professional help to get over this. Good luck!