Help please

I've owned an Xpulse for over a year now. My left hand has developed nerve issues possibly because my hands are a bit small for the clutch and I need to overextend. My height is 5'8 but my hands are unusually small, like a 5'1 person has bigger hands. I guess it may be due to my posture/ riding style as well because I tend to hunch a bit since I usually have a heavy backpack (not a pillion an actual one lol) Can I please get some tips on how to stop my problems? Both exercises, improvements to my own posture as well as modifications to the bike.