What's wrong with me?

So in the past 6 months ive lost about 40 pounds. I'm 13 i was 202 but slimmed down to the 160's. Because my volleyball season was over, i stopped exercising twice a week for 4 hours and went to nothing. I saw a slight weight increase of about two pounds. So summer has started and ive been working out more rigorously and longer, 4 days a week for 4 hours each day. It's been about two weeks.... and now i'm really hungry all the time so i guess i eat maybe more than average. So within these two weeks... ive gained 5 pounds going from the 161 i was from gaining those two pounds to 166. I'm not sure if this is normal because when i started exercising and loosing weight 6 months ago i experienced a slight weight increase of 1 pound which i assumed was muscle. So can you guys tell me if this is normal for all the exercising i do or is the weight gain from me eating more than normal? thank you! all answers appreciated and the exercise i do now is swimming.