Why does my interests change on a dime?

Ever since I got my laptop a 8 years ago I've had more career picks and little interests and hobbies that have come in and out of my mind. They make cycles that can last anywhere from a couple weeks to years on end and its really beginning to make my mind a wreck. I mean to get all worked up over something just to have the logical part of myself tell me it'll all be over within a couple weeks to a day is just irritating. My interests have ranged from Trains, Model railroading, model cars computer research and repair, to the Titanic to musical instruments (Electric b and Trombone) to cars and engine repair just to name a few. I will go ahead and say when I get into something I lose sleep over it and get obsessed. I literally eat, sleep, and breathe it like it's a pion just to have it disappear. My most recent project is getting my model trainset to run again which has wasted a good more than 20 hours of time in the last couple of days. Is it due to overexposure? Is it something I can change? Anyone that answers this will make an unprecedented difference in my life. Thanks and have a good day.