Ariel Winter Ariel Winter

Ariel Winter has grown up before our very eyes over the course of six seasons on ABC's Modern Family. But increasing commentary about her physique and repeated references to her "blossoming into a teenager" eventually drove the 17-year-old actress to get breast reduction surgery in June, she tells Glamour.

Winter says her development "really did happen overnight" and that by the time she was 15, she was an F-cup. "I remember being in my sister's wedding and being so flat and thinking, 'I just wish I would grow boobs!' and then overnight I did," she tells Glamour. "But then they kept growing and growing and growing, and it didn't seem like they were going to stop."

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The side effects of her growth spurt included severe back and neck pain that prevented her from standing up straight, as well as low self-esteem sparked by several disastrous clothes shopping excursions. "I really felt bad about myself. I didn't feel happy," she admits. "I just kept saying, 'What am I going to wear?' ... I can't go to a party with my friends and wear the same thing as them. I have to be completely covered up otherwise I'll look a certain way that I'm not intending to look."

Parties with friends weren't the only problem. Winter says her Modern Family wardrobe was often reduced to baggy sweaters, and she also got criticized by online commenters about her attire at awards shows. "It was really hard," she tells Glamour. "There was so little that I could wear that was age-appropriate. I'd have to wear the dress that was super tight and form-fitted everywhere because if I didn't, it didn't look good. ... Everyone would [say], 'Why is she dressing so mature? That's so inappropriate for her age!' I understood what they were saying. It's not like I wanted to pick out those inappropriate dresses. It's just that I didn't really have another choice, or I was going to get ridiculed."

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And so, she decided to have an operation to fix it (as some other women in her family have also done, she notes). She shared the news with some family members and friends, as well as her onscreen mom, Julie Bowen.

Winter says her other co-stars have been completely supportive (even if they don't all vocalize it). "[Sofia Vergara] was like, 'Oh, my God! I love them! They're great!'" Winter says. "It's funny, it's like the guys don't want to say anything, so they don't and they just are like, 'There's a change.' ... Everyone is really happy for me and has been super supportive. They understand I've been struggling with this for so many years."

"I have felt more happy with myself than I ever have," she adds. "I can't even really put it into words about how amazing it feels to really feel right."

Read Winter's full interview with Glamour here.