Can we ever say goodbye? When we lose someone we love, a goodbye, a hug, a kiss, just isn't really enough. What we need is more time!
So although you couldn't say goodbye, your special bond exists. Your friend sees your pain, and although you can't see or touch her she is with you and watching over you. Talk to her. Ask her for assistance in some minor everyday thing, e.g., if you've misplaced you keys, ask for her help finding them. Talk a little at time and in time, you'll be sure she's by your side in spirit.
Sorry for this devastating loss.