I'm Sorry

This is a bit of a message to my friend.
I want to say Sorry. We live so far apart and I met her on holiday but we promised each other we would stay friends and so far we have. Yet the strains of not seeing each other and living so far apart, makes our friendship difficult.
 We have different lives and so our only ways of communicating through the day is via text, however if one is having a bad day, they might not necessarily text the other, so a miscommunication happens.
 I really do miss her and I just want to say nobody is perfect.
I'm sorry, being such a happy person makes my low moments incredibly low and sometimes that means I say/write things I don't mean.
Sorry.
xx