My first advice is keep doing part of what you are now- take it slow and donít risk re-injury, I am NOT an expert but it seems to me that if you started running in 01/10 and did five 5k races in eight months you were overdoing it..
Since you are a runner I wonít go into a discussion of chronic cardio BUT I do suggest you up your walking and cut back the running mileage till you get back in shape. The weight you gained could be lean muscle mass from the free weights so give it a little time. Donít get frustrated, keep lifting, walk more(I suggest 3-4 times a week for 15-20 minutes to start and work up to 30-45 minutes), try cycling your carbs and calories (maybe with intermittent fasting) and remember that fitness is a life time journey.
Since you have come here asking advice I suggest toy read Markís Primal Blueprint 101.
As to the Whey protein: 140 calories and 4 grams of carbs seems low but I have to point out a 3 oz. serving of lean beef has only about 123 calories, ZERO carbs, 21 grams of protein and is a good source of vitamin C and Iron.
Because how we spend our days is, of course, how we spend our lives.Ē
~ Annie Dillard