My poorly rose

If you can plant it in a garden bed it might be happier.

Some of the soil in our garden pots has become very compacted over the winter which can't be good for the roots, we're going to have to investigate.

I'm a ruthless pruner too, I'd have hacked it down further although DH would be trying to stop me. The roses seem quite happy after a good prune (probably too late for yours this year now).

I’d check the soil for vine weevils. This is a common cause of previously healthy potted plants going into a decline.
They eat the roots.

We use bone meal. Perhaps that might help.

It might be happier in the ground or in a larger pot (at least 40cm diameter). If you’re going to replant, sprinkle mycorrhizal fungi on the roots and give it some food - better late than never.

I’ll give a feed and see what happens I’ll be very sad if it dies it was given to me in memory of my late husband.

I’d try some Mycorrhizal fungi, it worked really well on my roses in pots. It definitely won’t kill it. I’ve put most of my roses into the garden now, as I don’t think they like pots long term, and they are looking much better this year.

I'd say feed your rose. It's normal practice to give the first feed in April. Good luck.
I remember someone telling me that their potted Camellia never flowered. They were impressed by the flowers on mine. When I asked if they fed their camellia the answer was 'No'.