Monotony collapses time; novelty unfolds it. You can exercise daily and eat healthily and live a long life, while experiencing a short one. If you spend your life sitting in a cubicle and passing papers, one day is bound to blend unmemorably into the next - and disappear. That’s why it’s so important to change routines regularly, and take vacations to exotic locales, and have as many new experiences as possible that can serve to anchor our memories. Creating new memories stretches out psychological time, and lengthens our perception of our lives.
You are the only person who is in charge of how you feel about yourself. Nobody else can possibly do that. You get to decide if you believe you are beautiful or not, and nobody can take it away from you. If someone suggests that you aren’t beautiful, you can consider how sad it is that they have such a limited view of beauty. You can consider how unfortunate it is that they have such an exaggerated sense of self-importance that they think you should care about what they think. You can also choose to realize that it has nothing at all to do with your beauty and everything to do with their limitations.