Drowning in debt, don't know where to start

400ixl

You still have £12k p.a for clothes?
£180 a month to entertainment (and I assume internet is in there)?
£100 a month to a mobile phone bill (I assume there is a handset in there, how long to go until that is paid off or are you a serial yearly upgrader)?
£315 for electricity for one person is very high. I see a high value house, is it large and old?
£380 for car insurance is over £4.5k a year. Is that right?
£200 for house insurance is £2,4k a year. Is this right?

Seems like you have some very expensive outgoings still, but equally probably lots missing as there are many blanks.

You appear to have more than enough cash, savings and investments to clear your debts so it looks like your issue is actually money management and understanding budgeting rather than a debt problem.

Clear the debts, set some proper budgets and then rebuild your savings / investments in a manageable way against the budgets without borrowing all the time.

stu12345_2

selling say 90% your stocks and shares and redeem majority  of cash in bank would take a massive chunk out of your debts

if you use 90% of it you're almost debt free, then calm down your old heavy spending habits,  try secure at least you are earning monthly what you say you can earn , eg large amount.

return the EV car by voluntary termination once you have paid the £3k and or get new key and alloy repair before you terminate your pcp

Floss

Are you insuring both cars? The company should be insuring the company vehicle.

Cut out the £1k a month clothes spending - you don't need anything new.

Surrender the other vehicle to get out of the £844 a month contract.

Pay off the Amex, M&S and Fluid from your current account.

Withdraw £45k from your ISA and pay off the other cards & the £12k loan.

Then you will be able to live off your income.

Andyjflet

Firstly, pay the £3k to take the personal car to 50% mid term point and hand it back, better to even borrow than pay the £844. The cut your spending and start paying off the debts, small ones first to boost your morale. 
For me this is all clouded, and I'm sure to you too, is that you have managed to jumble up all the business and personal outgoings by the look of it. 

Meagainsttheworld

Brilliant, thanks guys. This is all really really helpful!