Depression from weight gain

I'm only 7 weeks pregnant but I look so fat! None of my clothes are fitting me. I tried to wear my favorite sports bra today and it was so tight I couldn't breathe 😭 I feel like people look at me and think I'm just letting myself go 😒 weight has always been a HUGE issue for me. At one point I was almost 200 pounds. I'm 5'6 😳 last year I worked my ass off and got down to 120. People told me I looked sick and had nothing nice to say about it. But I felt GOOD. I was happy in my own skin. I was 135 when I found out I was pregnant. Even at 135 my self esteem was plummeting. I haven't weighed myself since but I feel like I'm up to 150 already. So uncomfortable with my body! The past couple days I've made it my goal to eat as healthy as possible and to get some exercise in. Today I feel pretty good and not as bloated but it's really a blow when I went to the mall and all the girls were walking around half naked in see through clothes 😡 I used to be that thin, now I'm pregnant and feel like an oompah loompah. I love this baby and want it to be healthy but I also want to be happy, comfortable, and a healthy body weight. What are your tips on staying healthy while pregnant and not gaining 100 pounds!?