Thank you for asking. I can understand your concern. Let me tell you take night fall is not related to weakness. It cannot cause weakness. It is an early ejaculation problem which may require medical treatment and it can be completely cured.
Next Steps
Kindly consult with or visit a sexologist. After a detailed assessment of the severity, he can advice you specific treatment.
Health Tips
For more information regarding this you can consult directly here on practo.