I have never heard of any insurance that will pay for neutering or another optional proceedure. It normally covers illness and accident only.

Sometimes there are local discounted neutering drives in particular areas, but you could have a long wait. There is also an injection that mimics neutering for a limited period, ask your vet how much it costs, you might be able to afford it while you save for the op.

Didn't you get a redundancy settlement?