constant battle raging in my head

So I am getting myself running again as I have majorly slacked off this school year. I am going to the gym tomorrow to get a run in I dont know how long I will run but I am just going to get to the gym and just run. I was really motivated earlier today, and I am still motivated, but now I have all these negative thoughts going on in my head. I have all these little voices in my head right now telling me that I am no longer a runner and cant do it. I have literally been battling with my self mentally for the last several hours. I know that most of this is just inside my head and I need to ignore it but it is hard. I need to focus on how good it makes me feel when I am running and on my goal of completing that 5k in may back at Nipmuc 10 years after I graduated. I know I wont be as fast as I was then I just want to be proud of myself for completing the 5K and running the whole thing. I am hoping that being on vacation this week (from one job at least) and really being able to focus on myself including my running will help me get some of my confidence back. Until I get into the swing of things its going to be a daily struggle with myself and I just have to accept that. I also just have to put positive pictures in my head of myself doing well.