21y Female. Ruined breasts after weight gain. Is it possible to get my old boobs back? (photos)

From your photos it appears you have lost some volume in the upper pole of your breast. This can be improved with an implant. See a board certified plastic surgeon near you to discuss your goals and learn about the different implant options. I've included a video I hope you find helpful.

Thanks for your question!
Yes it's possible! Schedule a consultation with a board certified plastic surgeon to discuss your options. Best wishes!

The picture is hard to interpret as it looks like the bottom photo was cut off. The decision process here depends on which look you are trying to achieve. If you are going for the top picture, lift with implants would do. If you are going for the middle picture, lift alone would likely be a great option.

As always, be sure to research who performs your surgery to ensure the best likelihood of a positive result.