If Harry had diabetes in fanfiction, his social life might change. He might be more cautious about going on long outings with friends. For example, when they plan a trip to Hogsmeade, he has to make sure he has everything he needs. Also, his confidence could be affected. He might worry about being a burden to his friends during dangerous situations like facing Death Eaters, because his diabetes could potentially slow them down. And his relationships with teachers might become more complex as they try to accommodate his condition while still maintaining the standards of Hogwarts.
Harry's life would be full of new challenges. He'd have to educate himself and those around him about diabetes. In the wizarding world, where most things are solved with magic, having a non - magical condition like diabetes would be quite difficult. He'd have to find a balance between using magic to help with his diabetes management, like using a spell to keep his insulin cool, and relying on muggle methods. His adventures would also be different. For example, when he's on the run with Ron and Hermione in 'The Deathly Hallows', he'd have to be extra vigilant about his diabetes supplies and how his condition was affected by their rough living conditions.