Feeling so lost

I have been seeing a wonderful girl for the past 9 months. We both have mental health issues, specifically OCD. She made me so happy up until about 2 months ago. Everything seemed to change overnight. I suddenly started feeling suffocated. I didn't want to go out and do anything, I just wanted to be alone. But being alone makes me sad so I find myself spending every night with her to avoid being alone. This isn't only affecting my relationship, I also feel disconnected from friends and doing just about anything. I saw my doctor and got celexa but it isn't work yet. I really need some encouragement. I want to fix my relationship and make the feelings come back. Please tell me there is hope! My therapist says there is, but it only see her once a week so its hard to feel supported.