Get outside. Watch the clouds. Feel your heart pounding. Glory in the sweat flowing like a river and pooling in your shoes.
Critical: Don't wait until you pass your daily energy peak to plan your run!
Like you, I'm a mid-afternoon runner - I literal start squirming around lunch time to get outside. I wish I were a morning runner (Trisha is), but I'm not and lack the discipline to do things I really don't like. But if I keep putting off my daily run past, say, 6pm, I'm on the downside of my energy peak and often find I can't get motivated to leave the house once I'm home with the girls.
I pack a gym bag with me to the office, break away by 4pm, put in my miles, shower and change and either go back to the office (if there's more to do) or go home by 5:30 to spend the rest of the evening with Trish, Molly and Macy.
Schedule your runs - put them on your calendar - give yourself time.
You can do it!