Trying to Get My 5K under 30

This is the thing --- I run and run and run. Then I time it and I just can't get that 5k under 30. This is disappointing to me, because not more than 8 months ago I could easily get there. As a matter of fact I was sitting on 27.32 minutes for the 5k and on my way to getting better! Well I haven't raced in ages so maybe if I did I just might surprise myself and get that 5k under 30. This year I have been plagued with shinsplints and hip problems. Maybe I'm just trying too hard. I was thinking, because I trailrun it is more difficult to max my numbers. Trailrunning tends to demand more of a person. You run gravel and grass and slippery rivers, and watching for roots, mud, wildlife, etc. Your concentration is different than city running. You are constantly distracted by these goods things which make for a great run! The time seems to fly. I would not give up trailrunning for the world!! Then...I go to the eye doctor and we talk about what I love to do. Running... Her response was, "Oh my god your not one those runners that are always clocking your runs and chastising yourself afterwords?" She took the words right out of my mouth! So I sweetly answered, "Yeeessss." I'm too busy racing myself! Isn't that what running is all about though.??! I love the challenge, so I thought... It's time to put the jogger back in the runner!