I'm sorry you are feeling this way. Firstly, if it matters to you and is causing you stress then it's worth trying to fix it no matter how small or harmless might seem to others.
If I understand correctly - you're concerned that the machines will be in use when you need them and you won't be able to get your washing done?
If this is the case, purchasing your own machine could be helpful?
If that's not possible for you then would it be feasible to try and create a schedule with the others in your building?
Otherwise, you could try to visit the laundry area to assess how busy it is at different times and on different days and then use that information to try and organise your washing to be done outside peak periods.
When you find yourself thinking about your washing (when it not relevant) you can try listening to music and engaging in a task which occupies you hands/body to force yourself to focus on something else.
I apologise if these suggestions are not helpful for you. I hope you find a way to manage this problem and that you feel better soon.
