I seriously think my only option is to default and wait until the debt is sold on where i can pay it back at an amout closer to what i actually owe rather than the crazy interest amount.
If you do this, Very and PayPal are very likely to either massively reduce your credit limits or completely take away your ability to use them - which means you'll be able to make payments to pay off your debt, but you won't be able to borrow from them anymore. They are both very risk averse lenders.
You can't get spot help with debt. If you can't service all three, the only thing you can do is write to Vanquis and ask them if they will freeze your interest for a while and help you to pay the debt back. They may well then stop you borrowing more with them and they don't have to agree, but they'd usually rather make an arrangement to pay than have you not pay anything.
If it's sold, they'll sell it for a lesser amount than what the debt is, but the new company will be entitled to pursue you for the full amount. If it gets sold to an aggressive company, they may well go for a CCJ if you have a history of not paying. Vanquis are well known for this.
If you've got no choice, don't pay it. Prioritise food, rent and council tax, of course. But be very aware of what not paying it will do to the rest of your accounts and your credit record.