One of the most useful lessons I've learned is that we can have contradictory thoughts and feelings at the same time. We may spend a lot of time trying to decide what is the 'right' answer or the 'right' thing to do, and arguing within ourself.
It can really help to replace the word BUT with the word AND, and then to figure out what is the best way forward.
Example: I'm really tired but I should go and visit my mother.
I'm really tired and I care about my mother so I want to do this too.
Acknowledging that both things are true can you help work out what is the most helpful thing to do in that particular situation. This may vary - sometimes it may be to rest, sometimes to make the visit.
Since a lot of decisions are not clear cut I have also found that using the phrase -
"what is going to be the most helpful thing to do?" is a good approach. This balances up what you may need for you, with what others may expect or demand.