Just keep on running, and do not chase a target pace. Your pace is what YOUR pace is. Your body AND mind need to adapt to running faster. The mind is impatient, but the body is punished by the running mistress if the mind rushes her. Once in a while, maybe once a week?, do little surges (not sprints) during your runs. For example, if you run at 7:00/km, try and do non-downhill sections (a few hundred meter, not kilometers!) at 5:30 to 6:00/km. Try and run hills as well, but do no do sprints up the hills (yet). Obviously hills are good for strength, and strength (and leg speed) is required for speed. But first the hills Don't do this during your longer runs as long runs are all about steady effort.
