Stretch marks!

I've always been more slender, until this year! I am a smaller person, 20 years old. I put on a lot of weight from the stress of school this year so this is new to me. I am having a really hard time dealing with it and need some encouraging words. I made a huge lifestyle change and am beginning to work out and put healthy foods into my body. But people would see me and say "oh you have nothing to worry about! You look just fine." And that's annoying because without my clothes!! RED stretch marks in my groin area and around my hips!! Any really good creams or things that help it?? I'm already doing my part and eating healthy and working out VIGOROUSLY! Just need some confidence 😞 I feel so bad about it and I can't believe I did this to my body. It's making me more sad that it probably should.