Really sorry you feel both feel so down about it. You are way more than half a relationship. You are whole people with whole lives to live and experiences to have and opinions to hold and fun to experience.
Be really kind to yourselves right now. Really kind. Listen to very gentle soft (not heartbroken) music and watch gently distracting trashy TV that isn't about relationships (Repair Shop, Bake Off, cosy crime etc) Eat some delicious food, especially stuff he didn't like.
Focus on making lists of stuff you always wanted to do which aren't dependent on another person or are easier alone - a course or training, a physical challenge, a change in job, reading some classic books, exploring some wellbeing stuff like journalling, meditating, therapy, yoga etc. Start doing some of this.
Focus on things you always wanted to do with family or friends and haven't yet got around to - a weekend or lunch with your mum or an old school friend, a holiday or day out with your DC.
It's normal to be heartbroken but please don't think life is not worth living just because someone has split with you. All the other aspects of life still exist. They are valuable and you are valuable and they can help support you through the pain: Friends, Family, Fitness, Learning, Career, Home Improvement, Nature, Hobbies, Skill development, Community life, Faith or belief systems (religious or political or eco). There's so much out there for you right now and in the future.