A couple of things -

Numb hands can mean that you're leaning on them too much. Improve your core strength so that you abdominals & back can help hold you in position. Planks are good for this.

Impingement in your neck can cause numbness in your hands. You mentioned that you ride low & forward. Try straightening up a little. Straining your neck backwards might be aggravating the nerves that are in your hands. It's all connected.

Finally, don't hunch your shoulders towards your ears. When you're riding, try to pull your elbows together. Your shoulders will go down. This was a tip from my physical therapist AFTER I had a cervical fusion because I didn't follow the aforementioned advice ( but I didn't know...)