Luckily, rhubarb is a fairly hardy plant, and it should recover for next year. However, your plants are probably not looking so great because all the energy of the plant has gone into producing all those flowers.
Cut out the flowers and feed the plants with fish emulsion and seaweed liquid fertilizer afterwards. Also dig in some blood and bone.
Here is a good, all-round recipe that is good for all your vegetables, not just rhubarb.
1 part fish emulsion 2 parts kelp (dried, powdered seaweed) 10 parts dried farmyard manure 50 part water
Mix in a large container. Cover. Leave to stand for 2 days, stirring occasionally.
To use pour half a pint around each of your plants and the other pint over the leaves. The best way to do this is to take a small tree branch and dip it into the brew and flick it over the leaves until it is finished. Apply twice during the growing season.
Do not use the leaves for a week after application, and wash and rinse well.
Summer is the time to feed your rhubarb plants anyway, as they are heavy feeders, and so by giving them a good feed after removing the flowers will definitely help.
So what should you do with the flowers now that you have removed them?
Well, they do make an attractive dried arrangement if you cut them and then hang them upside to dry out before using.
You can also eat the rhubarb flowers. Making sure that you just have the flowers, soak for 30 minutes in salted water. Remove and drain.
Make a thin batter and dip the flowers into the batter and deep fry. Remove from the fat, dip into sugar and eat.