I can't help but obsess over my weight 😔

Since I was young I've always been overweight and unhappy about it , my weight was always on my mind . I have been on a constant diet for the past 10 years always failing. Whether it be after a day, week or month. Until about a year ago when I weighed in at 13st 2lb and I'm 5'2 I thought enough is enough. I started a carb restricted diet and managed to drop down to 10st 5lb (lightest I've ever been) I was so pleased and confident it changed everything!  I had new found confidence to wear nice clothes and feel great even in the bedroom wearing sexy underwear and didn't get embarrassed. Then Christmas hit and I let my self loose control. I jumped up to 11st 5lb and felt disgusted, when I looked in the mirror I felt 10x bigger than I did back when I was 13st 2lb which I know is ridiculous because I couldn't possibly be that size. Since then I have gone back to restarting a diet every few days after binge eating. I think I made a mistake doing a no carb diet as prior to that a bowl of special k cereal was a healthy breakfast but now I feel as though I've failed. If I eat anything over than what I was allowing my self on the low carb diet I felt like I was cheating. I'm ashamed to say I turned to throwing it up afterwards which in turn made me feel worse. I found out I'm pregnant 4 weeks ago and I weigh 11st 10lb now and I can't stop obsessing over my weight. Btw I stopped making my self sick before I found this out and haven't done it since. I know I'm going to gain weight during the pregnancy but it's really getting me down ... I really don't want to be at that 13st 2lb ever again ... I'm constantly thinking about it when I should be enjoying this time. I know I need to change my mind set but I just don't know how to when I feel so disgusting and ugly. 

Is anyone else struggling with this ? 😥