Was one thing.
Where we are now is another.
Do we still want to be together?
One simple question do you love him/her?
Is your love unconditional?
If it is not unconditional then you are in some kind of contractual relationship.
If it is unconditional then you can work things out or let him/her go because that's what unconditional means.
If no then what are the terms of your spoken or unspoken agreement?
Then stay and make the most of it.
Something changed, then time to consider, maybe time to move on or out.
Do not stay together for the sake of it.
If things have changed then acknowledge this.Be honest with yourself and your partner.