It sucks big time for a while, there’s no set time for how long. What I can tell you is once some of that fog has cleared and you can focus on yourself, you can learn to fall in love with yourself again. At least for me, I realized I had my positive emotions tied so much into my old relationship that I didn’t know how to cope without that relationship there. We definitely had some co-depency issues that were extremely unhealthy, and without all that to distract me, I could finally start working on myself and figuring out who I am. What I want and don’t want. It’s a long road but if you can focus on self care and improvement, it will make things much easier and more fulfilling in the long run.