My male beardie dragon is not eating much and is acting crazy!?

Yes, he could be in breeding mode, shame you didn't give bit more info like how long you've had him, how old the uv tube is and what temperatures you run him at. The fact that he is lively, jumping around is good, hiding away in a corner would not be so good. The temperature being incorrect and the uv needing replacing would affect the appetite which is why I'm asking. If you have a reptiglo uv tube, that would need changing every 6 months, if it's an arcadia 12% (these are definitely better) they have to be changed every 12 months. I can't say which temperature is best to run him at as it depends where the sensor off the thermostat is in relation to the bulb, but you should be aiming for a cold end temperature of 80f with a basking spot of 100f - 110f, then dropping your night time temperature by about 10degrees. Check these few details and you feel that everything is ok then I wwouldn'tworry. How many days a week are you feeding him? As beardies get older they do need less food, so instead of feeding daily, by the time they are 2 years old you could probably feed him 4 or 5 days out of the 7, and on the days that you feed him he will eat better as you are allowing him to become more hungry on the non feed days. Good luck, I am sure he will be fine but if he shows any other signs of illness then ofcourse you must take him to a vet or aat leastdrop him into a specialist reptile shop for them to have look at him, customers do that a lot with us and if we think it necessary then we will certainly recommend the vet.