Distance. For me, it works best. Some say that distance makes the heart grow fonder, but for me, it takes the acute sting of 'why can't I be with this person' away.
Do you talk to her online or on the phone or via SMS a lot still? See her weekly? Curb that down a little. Explain to her why. She'll understand and might even be grateful for a little pause.
When I broke up with my ex, he still called me everyday like nothing had happened. It went on for about a week and they had to ask him to stop calling because I couldn't handle it, just chatting about everyday things with him when there was this huge open wound where my heart was supposed to be.
Me: bi female in my twenties