I agree with you and Joy, some more value contrasts would be helpful. I always put a little pencil arrow in the corner where my light is coming from and then think about what would be in shadow.
Jade, nice job. One day you are going to discover the dark is your friend and that you can forget all those old spook stories you heard as a kid and find pleasure in your new friend.
I've had a challenge sometimes getting good darks with graphite. Something I found helpful was to use a higher number pencil like an 8 if you aren't doing that already.
I don't think there is a 6hb. It's either 6h or 6b. 6h is very hard and light, 6b is soft and dark. HB without a number is in the middle between hard and soft. Hope this helps.