If you can get a high street bank to refinance this for you, a £4,500 loan over 5 years, should cost you around 100 per month.
Can you start applying in the morning to see if you can get approval? Make sure to put in your application that it's to refinance more expensive debt so they don't include it.
I really think you are crazy not charging your children rent. £70 each a month plus your £100 covers the repayments.
Are they aware of your situation?
Do you know anyone who would lend you the money and you could pay them back?
If it was a sibling of mine, I would do provided they wouldn't borrow anything else until I was repaid
The problem with Littlewoods debt is the rate is too high to stop increasing the loan if you aren't paying the full amount. It will keep snowballing.
Ring them,even ask of you csn clear the £2500 within 30 days will they forgive the rest? Tell them you had a bereavement and lost track of the timing. Then find a loan to take out the amount.
if none of the above is doable talk to stepchange.