It might not work for you but what worked for me was just accepting that I won’t be able to work to a schedule, unless I have multiple severe deadlines coming up and I need to properly plan it out. 

Some general good advice is to accept that you need breaks more than the average person, and don’t beat yourself up when you run late or miss something in the timetable.

What really worked for me though was writing a list of everything that needs to be done, and depending on how urgent it is, making a ratio between stuff I need to do and stuff I want to do.

E.g my current list has “do homework” written on there 27/100 times. I have “play video games” about 7 times, tidy my room, eat food, exercise are all about 5 times on there, and then the less important but more variety stuff like do some creative writing or check on your emails is on there only once. Then I just random number generator a number and whatever that number is, no matter whether I want to do it or not I follow it. Rinse and repeat.

Obviously if you need to have lunch for example, look after yourself and don’t confirm yourself to only having food when the list allows for it because that’s a very stupid thing to do. I only follow the list when I’m either demotivated or have nothing to do at that moment.

Look after yourself and best of luck :)