If you are now living on your own in your property, you must notify your local authority so that you are entitled to a reduction in the amount of council tax you have to pay.
Council tax is based on the assumption that your property is occupied by two adults.
You must therefore go online at your local authority council tax web site and notify them that you are now the only adult in the property and ask for the 25% reduction.
You should also be aware that if you are on a low income and your savings are low, you may be entitled to council tax beneﬁt by way of help in paying your council tax. I suggest you contact your local authority to whom you pay council tax for further information.