Fears????

So I'm doing the whole Couch-to-5K program right now to help me ease into distance running and I'm having a hell of a time getting past 5 minutes of solid run time.  Granted I know that I'm not built like most runners.  I still have A LOT of weight to lose but I figured by now I should be able to run more than 5 minutes and not feel like I'm going to puke.

So my question is this....Am I afraid but just don't know it? Am I not running correctly?

The gym I belong to (Jack's Gym @ Wells Fargo) has a running club and they are starting outdoor group runs in April.  This will be lead by one of the trainers that works there.  There are 5 trainers total at the gym and 2 of them have qualified to run in the big dance...BOSTON!  In April I am going to start doing personal training with them.  I'll do the group run on Monday at noon, personal training with them on Tuesday.  PT will just be strength and cardio mix.  Run one on one with the trainer and Thursday and Friday will be my own gig.  Friday I'll run more to keep with the Monday, Wednesday, Friday run schedule.

I'm hoping this will help me.  Come hell or high water I am doing the half marathon in October.  Even if it means I have to walk most of it...I don't care...I'm finishing!!  My goal is not to walk or to walk just a little.

One of the things I'm working on that is really building my character is giving myself the benefit of the doubt.  I have a very hard time giving myself credit and I'm also afraid of success.  I know that is so stupid isn't it?  My failure of success is once I hit that goal then what?  What will be expected of me?  What if I gain it all back?  I realize these things are all dumb and "self doubt" but these are fears I've had.  I'm breaking these fears down slowly but surely.  I guess you could say the fears are breaking down like my weight....slow and steady!!