My boyfriend will be in recovery for many many months (9). You miss her. That is natural. I miss him but like others are saying, use this time to focus on yourself and your sobriety. Do you go to AA meetings? If you are healthy when she is out, it will be the best thing for both of you. You will be working on yourself while she is working on herself. If you stay down and depressed in her absence, that isn't supporting her right? Won't she want you to be healthy? If you stay down and depressed you may start drinking heavily again and if she is sober, she won't be able to hang out with you because it will risk her recovery. That is why you need to take care of YOU. You benefit, she benefits and it will all be ok.
IF you are really despondent, talk to someone.. lots of places offer free counseling. Definately seek out AA for yourself, you won't feel as isolated in her absence. They've been where you have been.