this is an adjustment period.... however, keep in mind, the splint is holding you in a healthy position at night while you sleep. The TMJ is being protected and in a comfortable position while you sleep. When you remove your splint, the first initial closing or having your upper and lower come together, OCCLUDING, now has placed the TMJ in unhealthy position. Therefore, causing you pain and discomfort with progressively getting worse as you continue throughout the day. Trying wearing part way through the day. See how you feel? Do you clench your teeth during the day or maybe most of your day? Did you know in total your teeth should only touch in total 10mins in a 24 hour time period! If you do clench, put a sticky note up that says" lips together teeth apart" The splint is working for you, at night only. I work in this field of dentistry and we treat our patients with a different type of splint. One that they must function in, eat, sleep, laugh, talk, everything! You only get to remove to clean it. Research TMJ disorders and disc displacement... Good luck!