I like the way your question was worded. You asked about diagnosis and about how you can manage your son's behavior. You recognize that diagnosis is not the solution. I recommend that you have your son evaluated by a local professional with expertise in diagnosing autism spectrum disorders. If he receives a diagnosis, the next step will be identifying services and getting recommendations. However, even if he does not receive a diagnosis, you will want to help him make some progress in the areas that you mentioned. It is interesting that your son shows some difficulties at home that he does not show at school. It is common for children to behave differently in different situations, and this reminds us that the environment has influence over children's behavior. It is likely that your son exerts more control over his physical and social environment at home because he can. His teacher cannot possible accomodate his preferences given that he/she is responsible for a large group of children, and he has learned to handle this situation. You are inclined to make your son happy and so you do what you can to accomodate him. You might consider identifying some rituals, routines, preferences that are problematic and then addressing those. For example, your son should not control when you go to bed. Teach your son to tolerate change by gradually introducing change under supportive circumstances. You can support your son by teaching him some strategies for dealing with unpredictability (e.g., relaxation or distraction) and rewarding his cooperation with these changes. At the same time, try to minimize attention to negative reactions to change. Please work to find a local professional who can help you to identify situations to target and work with you on a plan for supporting your son.