Samir, thats quite an improvement over yesterday where you managed 8 miles in 1 hour.
As cougie said, you have a very slim chance of qualifying for the marathon.
Most marathoners start at the middle distances (5k and 10k) and then move up to the marathon distance. If you are serious, you need to focus on the 5k distance and complete a road race in under 15 mins, before moving up to 10k etc. NB I'm not sure what the current international 5k standard is, but a quick look at a couple of small, local 5ks I ran had the top runners coming in just over 15 min, so you need to be faster than them - its probable you need to be a good few minutes quicker than this to be international level.
Have you thought of pursuing your football or boxing ambitions? Not only do they have more competitors in the GB team, so you must have more chance of getting in, the marathon is probably the most physically demanding of all events to pick.