feeling gloomy and "overweight"

I've never struggled with my body image before but ever since I went to the doctor and get weighted I've started to worry. . I play volleyball and run track. I usually am around 145-150 pounds but it's gone up to 155(I'm 5'8 and 15 years old) I think it's just me gaining muscle but I'm beginning to worry my diet is too poor. I don't eat super unhealthy but I wouldn't say I eat the healthisest. But it balanaces out with track and volleyball(I know that isn't an excuse to eat unhealthy) we usually go to zupas or Panera or subway or even noodles and company if we're not home to cook which is often. I'm trying to eat healthier because I enjoy it but it's so difficult when you're on the go. I'm going to include and picture and if anybody had any advice for me to stop feeling guilty and "overweight"and also some healthy in the go snack ideas