how long is this pain going to last?

The relationship was 20 months, she lived with me for a year, and we broke up 5 months ago. I am still having obsessive thoughts, trouble concentrating at work, and trouble sleeping. I have dated some, been seeing a counselor once a week for 4 months, and only see/talk to my ex about 1-2x a month. The contact is typically not by choice, although I did call her about a Bible she left (I've tossed everything else). It's a small city, we have friends in common, and I have tried to be cordial rather than avoidant. I don't want her to know that I'm still hurting.

To be completely candid, I'm miserable. When is this going to end?