I feel bad

Whenever I eat sweets, I feel bad. I feel like a miserable failure and like I have no purpose in life, I might as well just die. And yet, I eat things I'm not "supposed" to eat almost every day. I never learn! I just cling on to how I "enjoy" these foods because I'm somehow supposed to, like I know that I enjoy them even though I don't feel it. I try to keep in mind that it's a lifestyle, not a diet, and today is my birthday and it's okay to have ice cream. I just feel like it's hard not to think in black and white, to know when to allow myself to have something and not to obsess over my eating. Sometimes I'm happy and sometimes I feel like a potato.