I relate and use to make things for my T, to give her when she was back or, when it was for a long period, to mail to her office week-to-week. See if you can focus on something that happens after she will be back; extending your future thought to something more solid and "normal" instead of free-range might help. I know when I was working on termination, for example, I started also working on my moving house and retiring and the travel that was going to take place a couple months after termination. In other words, build a "bridge" to beyond when she will be back and you won't feel so much like she could have drowned in the river while you stood on the near bank.