I am so tired even salaah feels heavy

I am a nurse in Conakry, daughter to two ageing parents who rely on me for appointments and medicines. After a twelve hour shift, the bus ride home is loud and my feet ache, and even dhikr feels like another thing on a list I am failing. I used to find barakah in serving them, but lately I time my prayers between pills and lunchboxes and feel guilty when my heart is empty. It is shameful to admit, but sometimes I skip tahajjud because I am simply too exhausted. Has anyone else been so burnt out that worship itself starts to feel like a task? How did you sit with that feeling?