It looks to me like your handle could also be smaller. This would allow for more limb to spread out the bend. You don't need much handle. When I first started making bows, I did the same thing. I made these really long handles until it occurred to me suddenly that as that part of the limb wasn't bending, it was just subtracting from my bow. I was following the general lengths you'd expect for a self bow (around 65'' for me), but I wasn't calculating the length of my non-bending handle into that calculation. So, there wasn't enough bendable limb going on. My limbs were overworking. I kept wondering why my bows were taking too much set when I was so careful during tillering. This was why.