If I assume your trying to get back home to the UK. The cheapest options are:
1. Sell any of your unwanted, surplus to requirements stuff on an online auction site.
From the proceeds, book an online air ticket with Easyjet. Catch a coach or bus from
Kiev to Warsaw Poland.
Proceed to the Etiuda air Terminal ( where the cheapskates fly from ) at Warsaw airport,
to catch your Easyjet flight to Luton airport or Bristol.
You cannot miss the Etiuda air terminal as all you have to do is follow any students with
a backpack.

Flights with Easyjet can be booked for the price of a pair of Levi jeans ( also its cheaper
to fly on a tuesday ) and Easyjet will love you if you bring little or no baggage.

2. Is same as above. Except this time you book a Ryanair flight from Riga, Latvia.
Obviously you need to catch a bus or coach from Kiev to Riga and then proceed to
Riga airport.
Advantages - again flights with Ryanair can be booked for the price of a pair of Levi
jeans ( and cheapest flying on a tuesday ) Far greater choice of UK destinations like
East Midlands airport in Nottingham, Glasgow, Liverpool and London Stanstead.
Again Ryanair will love you if you bring little or no baggage.

Disadvantages - you might need a Belarus visa to transit through Belarus to Latvia.
I have heard of a no frills Latvian airline, thats started up recently that might have
some eastern european connections with Ukraine ??