I don't see motion add in here, but essentially what you want to do is keep track of your horizontal speed and vertical speed separately. And then use point_direction(0,0,hsp, vsp) to turn that into a direction, and point_distance(0,0,hsp,vsp) to turn it into a speed to pass to the script. I also recommend not using image_angle, as this will also rotate your collision mask which could cause problems. Create a new variable to handle the display of a rotated sprite and draw the sprite in the draw event using draw_sprite_ext() with this new variable substituted for image_angle.