You never know which sin in particular is standing in the way of your duas. Or which sin is standing between you and the sweetness of iman that you used to feel.
Imam Ibn al-Jawzi رحمه الله said:
"As long as your soul breaks under admonition, and your eyes weep during reminders, know that there is still life within your heart."
صيد الخاطر
It was written on a grave:
"نعم المسكن لمن أحسن"
"What a blessed home for the "ahsan"!"
(Someone who is driven by deep consciousness of Allah ta'ala and strives for excellence and beauty in everything they do to earn His Pleasure)