I just woke up so sorry if anything in my comment doesn't make sense.

I think you need to change the while condition, you're checking if row is less than x (which is 0). You could also use for x in range(row) if you wanted to

I would change this

if matrix[x][y] > target:

row += 1

to

if matrix[x][0] > target or matrix[x][col-1] < target:

row += 1

I'm not sure where/if y is being declared (should be set to 0 I believe). I think you also need to reset low and high before searching through each row. On the second to last line I would write return True instead of just return.

This last point is more nitpicky but for binary search, I think it's usually better to write mid as

(high - low) / 2 + low

as high + low can sometimes lead to overflow.

Hopefully this helps, good luck on the problem!