Rough Winter training Cycle

I started to train for a marathon in preparation of a Full Ironman in the later summer, although it did not seem to go as expected. With all of the cold temperatures and snow and my schedule it seemed to be tough to complete the takes by the expected date Jan 29th. Although I took a couple weeks off and then, have tried to start back up. I have since moved my training and in the mean time of 2 weeks of not running I have gained 4-5 pounds. There seems to be alot of other distractions that are not allowing me to focus my time on training, and the time commitment that is necessary makes it very tough. Went on a 4 mile run and it seemed to be a breeze, but then knee pain after the run?????? Not sure what that was about.