Make sure you do a few dry runs to check that you can comfortably do it all off the top of your head, and that your timing is decent (1-2 mins over/under is fine). Also, the most important thing is to take your time and don't panic. If you lose your place, just take a breath and refocus.
People don't normally speak in rapid fire, or treat silence like an enemy - giving a speech is no different. Silence can add emphasis and also lets people know you're confident in your delivery and won't be umming and ahhhing. Also, as others have said - intro, topic, conclusion helps audiences follow what you're saying.
