Taking your considerations into account, bikes we would recommend taking a look at are the Triumph Speed 400 and Scrambler 400 X / XC.
Both will offer you considerably higher performance than your Yezdi bike and will also be comfortable enough to handle daily commuting duties while being brisk enough on the highway as well.
If you want an air-cooled, torquey engine, then you could even take a look at the Harley-Davidson X440, which is a comfortable neo-retro roadster that has decent performance.
Take a test ride of the machines you shortlist before picking one.

