i am considering retiring from work at 58 ..

xylophone

State Pension Forecast here
https://www.gov.uk/check-state-pension

Albermarle

.i could draw £100 per week of the £48,000 and it would last me till im 67 //t

Presumably you have calculated this on the basis of the £48K being kept in a savings account . 

Ideally you should invest some of it to try and get some better growth . Otherwise at least try and maximise the savings interest by searching for the best paying accounts and tying most of it up in fixed term savings which pay better . Some for one year, some for two years, some for five years etc .

https://moneyfacts.co.uk/savings-accounts/

bluenose1

The experts on here will know better than me but would it be worth maximising how much you can put in a SIPP in the year you retire. For every  £80 into SIPP it will be topped up to £100. You can then withdraw this tax free as long as you stay below the £12,500 personal allowance. I am going to do a cash SIPP in my last year of work to the max I can . Also for future years each year you can put in £2880 and it will be topped up to £3600, even if not working.
i think you definitely have options to make best use of your income.