Work according to the amount of energy your body can produce at the moment. Stop if you feel tired.
Quran orders us not to put ourselves in difficulty.
Let me give you an example.
Its human nature to forget. The reason is not that we are made that way. Its just that we forget things that we don't concentrate on.
My family sometimes get our clothes washed at a nearby laundry. Every time I go there, the thing that impresses me most is how well the laundry man remembers where he keeps whose clothes. He doesn't uses any kind of tags. Its all in his memory. Today I asked him about it. I asked him, was his memory the same way when he first started in this job. He said no, it happened over time.
And I kept thinking about this. Before this I didn't thought that improving once memory was that important. You can always use aids like dairies and mobile devices. But this made me realize that if we can improve our memory without making this process of improving a burden, it would make our lives easier.
Similarly we can also improve our habits or our lifestyles. All you have to do is allow yourself to change out of a particular style, slowly. If you make a mistake, let it be. But the important thing here is not to give up. And always work with a teacher to learn something new.
Quran orders us to learn new things only from a teacher and not on our own. But Allah takes the responsibility of teaching you Quran if you read it in the language you understand. You don't need a teacher to learn Islam.
So please be a part of this universe and move gradually and allow others to do so.