It's clearly a bug and from the stories I read in this great Forum The cure nor the vaccine available yet.
Yes, some have likened it to an addiction and it's certainly as powerful. You were doing ok, and then you saw her, and then you felt like you were back at the start.
We've all had that feeling of totally relapsing and that the intervening time has been for nothing. But it hasn't.
There is a cure, Sinister, and the cure then becomes the vaccine.
The cure is to grieve fully, understand what the relationship meant to you, why you wanted it, what need it filled, learn that in a deep way, keep re-learning it every day for a while and, gradually, the attachment lessens its grip on you.
If you work at it, here with us, and for yourself, you WILL notice a result and that will help you to move forward and be free and healthier. I know it doesn't feel that way right now, but as much as we all may have wished for a pill to just make the whole thing go away, it's endlessly more empowering to realise that you produce pretty much all the chemicals you need to process this all by yourself.
Have you thought about some of the stuff that you liked and didn't like about the relationship? What are the things?