Freaking about weight gain!

Logan
I started this pregnancy at 136lbs. At my last doctors appointment at 22 weeks I weighed 151. I just weighed myself this morning and my scale said 157!!! I gained 6lbs in two weeks?!?! Yes my appetite has increased like crazy where I feel like my stomach is always growling but I didn't think I was eating that bad. I very very rarely eat any fast food and I will occasionally eat one of those small kid sized bags of chips. I allow one Dr Pepper can a day to help with my headaches but drink water the rest of the day. I try to eat lots of fruit and vegetables and have tried staying active by deep cleaning my house and walking with my son. 
I'm kind of freaking out about my end weight and possibly gestational diabetes. Am I going crazy or do I need to really make a change somewhere?