Sorry to hear your woes and you have been unlucky with the manure, which is best stacked until more rotted, do grow squash and courgette on it after making as tidy a heap as possible.
As for green waste compost, when I first used it the quality was higher than now when there is often more wood included, which takes nutrients until it is decomposed. It is good when used with some well rotted manure and I have been doing that here at Homeacres.
Steph had a similar problem last year when she inherited some beds of pure green waste compost, and she spread some comfrey pellets and seaweed meal to help enrich it. She didn’t even rake it in but it was raining all the time! This year I would rake it in lightly to the top couple of inches, except where you have already planted, water in if possible.
Another idea is to water with nettle tea if you have stinging nettles, which are high in nitrogen, soaking them in water is the quickest way (two weeks) to extract goodness, but smelly. Otherwise they can be squashed into a pot with a hole in the bottom and the black liquid can ooze out of the bottom into a bucket – that way there is no smell, takes two months.
Whatever happens it will come good in the end but you are in for a tricky spring and good luck with it.