Out of shape

I did 5.8 miles with Run Club tonight at just under 8:00 pace and felt like I was going to die. A few months ago that pace would have been an easy pace for me. I knew I was going to lose fitness by taking time off, but its still hard mentally to accept the results. I've got a long road back to getting back in shape. I know it will only take a few weeks of consistent running to get back to feeling decent, but its still hard to accept.