Oh the joy of BPs. 5 months is a decent fast but I wouldn't be too worried yet. A couple of my carpets are just starting to take food again. They hadn't eaten since November or December either. Hopefully yours will get back in the groove soon too. At the 6 month mark you could try a different prey type or a small live feeder. He's 4 years old and if he was eating weekly before he'll definitely eat again eventually. You may even want to extend him to a 10-14 feeding schedule