before my first marathon (Amsterdam 2006), I averaged three runs per week and a total weekly mileage of about 25 miles. I did the marathon in 2:57. A typical running week for me at that time involved one track session, one hilly run and one long run
into manageable portions e.g. the next gate/lamp post/tree/parked car/whatever. Keep track of your progress – it’s worth singling out one or two key landmarks on each hill and reminding yourself (in a few weeks’ time) that you've been able to get much further