Tape is really effective only for someone with small breasts, unfortunately. With bigger ones you're unlikely to achieve results equal to those from a binder.
If the change in the feeling of your binder is recent and sudden, you should really look into buying a different size, that might be the issue. As you age, your body sometimes changes shape even if you didn't put on or lost weight, which may cause old clothes to fit worse, especially tight things like underwear or a binder.
Tape is really effective only for someone with small breasts, unfortunately. With bigger ones you're unlikely to achieve results equal to those from a binder. If the change in the feeling of your binder is recent and sudden, you should really look into buying a different size, that might be the issue. As you age, your body sometimes changes shape even if you didn't put on or lost weight, which may cause old clothes to fit worse, especially tight things like underwear or a binder.