I'm turning 16 and have a similar problems, like fixation on certain topics like aircrafts, history and astronomy, also I to can't be bothered to take showers every day. Would you try my advise on making a plan of action for everyday and make you watch/phone go of every hour so you don't get into "memorisation". Since us who have autism like routines. But don't make them to exact(the mistake I make) so you don't stress out since we're not robots. Hope that'll help you a bit thank you for your time.
I will try that. Thanks for the advice!
Our son is 20. Struggling with the same issues. Have you thought about posting a list on your bathroom mirror. Maybe posting on your calendar. Wishing you the best.