My company is laying people off and I am not a victim, but it feels like I am. Any advice?

I am a software engineer. The company I work for is in the process of laying off a large percentage of the workforce. Many people on my team have been let go, including one of my closest friends at the company. I just feel sad about it. I feel like I need to step back a little and move on. I don’t feel like contributing a lot and I am afraid my performance will suffer. Does anyone else have something like this happen to them? How did you move on?