an object is in orbit because both centrifugal force and force of gravity are in balance or are equal

gravitational formula stablishes that force of gravity varies with distance dividing by the distance squared, im gonna prove aplying conservation of momentum that centrifugal force varies with dividing the distance to the cube with which is imposible both are in balance if the radius varies as happens in ellipses

imagine a universe with such a gravitational constant that theres a sun and a planet orbiting each other and both weight 1 kg:

in the perihelium the planet has a speed of 2m/s and is at a distance of the sun of 1 m in the aphelium speed is 1 m/s and distance is 2 m

now lets apply the centrifugal force formula f=m*v*v/r

peri: Fc=1*2*2/1=4

aphe:Fc=1*1*1/2=0.5

so with a distance of 1 m theres a centrifugal force and therefore of gravity since the object is in orbit of 4N

and with a distance of 2 m theres a centrifugal force of 0.5N

so centrifugal force taking into acount conservation of momentum varies dividing by the radius elevated to 3

then how can gravity vary dividing by the radius squared while centrifugal force varies dividing by the distance to the cube

its imposible both balance as to make an orbit varying one dividing distance squared and the other distance to the cube

whats going on here?