I have a problem that i cant focus on my tasks for a long time. I cant do my work for long time per day, neither do it periodically every day.

I know that to develop habits of doing certain work every day, i need twenty one days, but i lose interest to doing my work and just becoming bored of it in two weeks maximum, which is not enough time to develop habits.

Another thing that my lazyness does to me, is that i cant keep my focus on one big task for long time, like several hours. I can keep working on this task for half of hour or a one hour at most, until i just get bored of it, and dont want to do it until next day.

This problem apllies to any tasks i need or want to do, like doing sports, home work, programming and other work, and this is what keeps me from getting a job, because i just cant work full work day every day, especially if i cant even develop a small program for home work for more than two hours.

Which advise can you recommend to get rid of the lazyness, and actually keep focus on the work and develop new habits?