Assume that earth shrinks but its mass remains the same. What happens to the value of your weight?

Answer 1

The weight W will increase with the decrease in the distance between the centers of masses R.

let W2 be weight as is and W1 weight on shrunken Earth.
W1=Fg1=GMm/R1^2
W2=Fg2=GMm/R2^2

W1/W2=GMm/R1^2/GMm/R2^2
W1/W2=1 /R1^2/ 1 /R2^2
W1/W2=(R2/ R1)^2
W1=W2 (R2/ R1)^2

let the radius shrink twice we have

W1= W2(1/0.5)^2
W1=4W2

The weight will increase 4 times.

Answer 2

As the earth shrinks the surface gravity increases so your weight goes up.
If you could shrink it down to about the size of a period on this page and it would become a black hole and the surface gravity would be such that the escape velocity would be greater than the speed of light.
However I believe that a black hole is a non viable entity.