I know what your problem is. I see it often in my teaching.
There is nothing wrong with the approach to the shot or your selection of shot. What you need to do is abbreviate the swing but at the same time execute the normal mechanics. So often I see golfers shorten their swing but then they forget to turn the club over at impact and they slice or block the shot.
This happens partly because the swing is shorter, therefore upright and more inside the line but also because you want to keep the shot low, the hands remian in front and unless you actually shut the face, it will be open when it reaches the ball - hence a shot to the right!
Do this for me at a practice range:
Take an 8-iron, grip down a bit and move the ball back, as if you were going to punch out, back onto a fairway.
Now, swing back to just passed your hips ... the toe of your club should be pointing directly at the sky. Your left arm should be ina stright line with the shaft. All ok so far?
Now, without actually swinging through, do the same post impact, just passed your hips. The toe of the club should be skyward, your right arm and shaft should be in a straight line.
That is the movement you need.
Go back to address, swing back and through, working the club face ... toe up, square, toe up. The ball should come out low and straight, maybe a bit of draw spin ...
When you have that under control lengthen the swing and repeat the drill with the rest of your
irons.