I looked at your position and believe the next steps from here are clear, based on 2 clues (treating this as a 6X6 matrix excluding top row and left column purely containing titles):
r2c1 and r2c2 and
r4c1 and r4c2
it is obvious that no other cell in these 2 columns can contain a 1.
Next, r1c5, if assigned a value of 8, results in a repetition of value of 3 in r2c3 and r2c4 so strike out the 8. Going forward, one can solve the rest of the puzzle, but I seem to get two valid results which goes against the basic rules of kakuro. So I guess this sum is suspect n the first place.