I Want a Lover Who Is Also My Best Friend

Im confused about whether this is positive or not. I met a wonderful friend online we became lovers. There was a very deep connection but now that the flame is dimming it is really hard to be friends like we were before.
Things happened too fast. I've always believed that a lover can be your best friend but now i doubt it. Perhaps it can be if you stay lovers forever but ive come to the conclusion lately that love or lust??? has the potential to ruin friendship.