Uhmmm, I thought I was ready

To start training again. Today's run just proved to me how severely my running skills have diminished over the past six weeks of three miles a day, six days a week and no long runs. Not good.
I went for a ten miler today, although I did not meet my goal of getting back out at seven on every Saturday morning. I was really on a roll there for the past two marathons. Today, I rolled over and looked at the temperature gauge...it said 24 degrees and I said no thank you to running that early. This is a very bad habit to cave into.
I was going to blow off the run entirely, but managed to give myself such an amazingly heavy guilt trip that I went out this afternoon. It did not go well.
I ran five outside and five on the treadmill. I just flat out gave up after the first five outside. I managed to convince myself that five was enough for the day. Then I gave myself another massive guilt trip and forced myself to finish the last five on the treadmill. Yet I'm still not happy with myself.
Although my pace was good (around an 8:40 average) I just didn't feel good about it. My lungs hurt, my face felt totally windburnt, and I just felt sluggish. Not very good for building up my confidence regarding tackling a higher mileage training plan than I've used in the past.
I'm going to still try it (I think) but I'm very uneasy about it. I'm not sure if it's the ambitious plan that's got me spooked or if I'm just burnt out. There were a couple of times today when I actually thought about not doing a spring marathon, and maybe just aiming for a half instead. That sounds so weak to me though.
I'm hoping that I get my head in the game a little bit more in the next couple of weeks. I'm ready to physically I think, but mentally I'm just not there yet.