I'm growing a plant for the first time .. it's been 1.5 months.. I'm from India. Sowed it in the starting of winters.. no frost but really cold now(4 ℃ to 20℃). The leaves have started yellowing and drying out from bottom up.

It was healthy just 10 days ago.
Don't know what happened!
HELP ME PLEASE!
Here are the photos.

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