Weight Increase from running

I decided to lace up the shoes and get back into running. I’m not doing it for weight loss (I actually think it makes aspects of weight loss harder). I just actually enjoy doing it and find myself less likely to partake in my other vices (that really effect weight loss) when doing it. Last time I did it I got addicted quick and just destroyed my legs. I was also loosing weight back then and remembered stalling for weeks on any progress. This time I did it I got addicted quick and destroyed my legs, I weigh about 4-5 pounds heavier than my low at the moment. My eating habits have also changed as I require more calories and have been killing more carbs (don’t care what anyone says running on anything other than straight carbs is torture.) How do I know what’s just water weight and if I’m eating too much? I have a really difficult time thinking I’m eating to much but it can be kinda hard when running 8 miles at 6’1 215 burns quite a bit of calories.