Why is pakistan worried about control of kashmir?

The reason is water, Pakistan is scared that in times of Conflict, India will stop or divert the water

The Indus Water Treaty, which was signed in 1960, has remained intact for more than 50 years even during periods of unrest. Under the treaty, India gained control over the Sutlej, Ravi, and Beas rivers, while Pakistan received control over Chenab, Indus, and Jhelum. However, since the Pakistan-controlled rivers first flow through India, in the background of mutual hostility and suspicion between the two countries, Pakistan has the tendency to believe that the water scarcity that they experience is somehow attributable to India (as opined by Ramaswamy Iyer, the former Secretary for Water Resources in India).

According to the Asian Development Bank report, Pakistan is one of the most water stressed countries in the entire world. According to projections, India will become water stressed by 2025. Pakistan is likely to be classified as water-scarce soon, and India is set to become water-scarce by the year 2050.

HERE IS THE FULL WEBSITE IF YOU WANT MORE INFORMATION

https://www.quora.com/Why-does-Pakistan-want-Kashmir-2