Another

Regret is normal. You left someone you cared about because something got in the way. Maybe it was them, maybe it was you, or maybe something outside of the two or few of you occurred and you couldn't control it. 

Do you regret what you did? Do you wish to go back, even when you know it was for the better? I've seen it so much. 

So many people try to go back to what was, and ultimately end up worse for it. I, too, have regrets like that. It's hard to battle your heart and your love for someone who'll only hurt you in the end. 

Take a deep breath and think about how everything could end up if you choose to go back. Think about the pros and the cons, what you can or can't control, what you can fix or break. 

Write them down and make your verdict on paper before you burn it. 

Maybe things are better off without them. You can find someone else to fill that void in the meantime. After all, you're here to make FRIENDs, are you not?