easiest way to get a good ref is have somebody in front od you holding a pole or baton at that angle.

Hmm, not sure if its just the perspective but it seems like the arm is too short. Also seems like the arm leads right into the hand without much definition of a wrist.

I just tried holding a clear tube to see what seems off and my fingers seem to grip around it differently than what you have drawn there.

I had a similar thought on the arm myself it just seemed the proportions were wrong and there wasn't enough wrist there causing the whole handful to fill a bit off

Sorry love, if I was on my computer id give you a hand (pun not intended).
Perspective is the main issue here and the diameter of the held object will effect how the fingers curl around the object. Make sure to also consider weight, that thing is really top heavy, the wilder would require a much firmer grip...

Take a look at these three references that show different object size and weight from small to large...

Top right (small/light): https://www.deviantart.com/cgcookie.....mple-356752497
Medium (with varying grip types): https://www.deviantart.com/melyssah.....rasp-378485326
Heavy (and thick): https://www.deviantart.com/humanana.....ails-187256118

Finally, keep in mind that your hand is almost as big as your face. Perspective again can be an issue here as things appear smaller at a distance but try playing around with the overall size of the hand (once you have the grip etc sorted) until it looks right.

Hope this helps!!