Little cat mean little loads. Ultimately, you are going to have a very difficult time balancing those huge boxes with that frame on those tubes. Sorry.
As Kenobi said, get the balance a little tiny bit forward of center. Have your buds tell you have your trim looks on the water then take up an hour of all of their time as you adjust each day.
I would suggest a simple trailer frame hoop to hang one of those boxes on in front of you. That will give you by far the best hope of getting decent balance. you could also put a camp table in front of you strapped across the tubes and pile dunnage and beer onto it. You can pack bags of beer and water jugs around your feet if you get (or have) a mesh floor.
You can also just pack less. Five days of gear for some is a box of ramen, a bottle, a blanket and a lighter, and they're often the happiest. Good luck.