Welcome to garden.org!!!!!!!!!!!!!! Great folks and information here.
I'm really not sure what to say. If the plants started out in bad shape they may never to the corner back to good health. Just looking at them without any knowledge of what they've been through it could be over watering, under watering, some type of disease, etc.,.
Did you give them any fertilizer? Good soil needs fertilizer added at times. Where are you located? If you're not in the far north then you could probably still start cucumbers from seed in the ground.