Do not continue a relationship for which a partner cannot make the time
If you want to build a close relationship with a child, it is insufficient just to hire a nanny or shower the child with gifts. You must also make personal time for the child. It works the same with a partner. No man is indispensable in a job and even more so in a relationship. And if a partner behaves as if he is indispensable, he should not be surprised when there is no place left for him in the relationship. Healthy relationships do not fall from the sky. They are built. There are masses of toil, compromise, communication behind a solid relationship. Plenty of failures, mistakes and lessons on one or the other side. But, as in a funnel, all these are aimed towards increased understanding, empathy and enhancement of a relationship.
In order to survive such a long and demanding process, the couple must be strong. And the relationship will be strong, if both partners strengthen it sufficiently. To be able to strengthen it, both partners must be strong themselves. Which is impossible in a relationship with a vampire. Because a vampire weakens the other partner. That is why a strong relationship cannot be built with a vampire. Only a strong dependence on what is slowly destroying you.