I've looked at a couple of councils and they both have this on their websites:
Single Person Discount
COUNCIL TAX 25% DISCOUNT
The full Council Tax bill assumes that there are two or more adults (i.e. people aged 18 or over) living in a dwelling. If you are the only adult living in your dwelling the council Tax bill can be reduced by 25%. To be considered for discount you will need to complete an application form.
n.b your income does not matter - I get 25% Second Adult Rebate as my 20 year old daughter is a student. So one income - 25% discount. Look up your council's web site and put in a claim this weekend.
You might be able to claim help with our council tax on the grounds of low income. Visit your local council website. I think that your income is too high though.
I pay �90 council tax and have less of an income than you and I wasn't entitled to help on the grounds of low income - but check your council site to put your mind at rest.