+1. You need to go pretty hard in your warm up. Gradually build up in warm up, until you do a couple of short maximal efforts. Something like this 10-15 minutes easy. 5 minutes at tempo times 2. 3 minutes at lactate threshold times 2, building to maximum effort for the last 30 seconds of these. Then 5 minutes easy, and to the line

Also, pace yourself. Devide the distance into Thirds. First third, go one notch easier than the pace you think you can hold for the whole distance; Second third, raise your effort to the pace you think you can hold; Third third, gradually ramp your effort until yo die at the line.

Definitely err on the side of going out too easy. No matter how much you try to go out easy, you're almost guatanteed to start too hard.