Weight Gain

So I will admit when I first found out I was pregnant I took full advantage of eating whatever I wanted to but at my 25wk appointment I had gained 13lbs in 1 month for a total weight gain of 33lbs. After seeing how fast I was gaining weight I have cut back and started watching everything I eat along with walking on the treadmill 30mins. everyday. It's been 2wks now of watching what I eat and walking everyday and I've already gained 5 more pounds in just 2 weeks. That puts me up to 27wks along with a weight gain of a whopping 38lbs so far. I just feel so out of control and disappointed in myself, I just don't know what to do. If you have any advice or words of encouragement I sure would appreciate them cause I'm at a loss.