Desperate breakup feelings

I know that I’m thinking thoughts (I’ll never find someone who can be as (insert trait) as this man. I’ll never be able to navigate life and have as much fun without this man. I’ll be a lonely, desperate ugly old cat lady. I’ll never have great sex again. I’lll never have sex THIS good again. If I couldn’t ask for what I wanted sexually with THIS guy, I have no hope in the future – he just knew what to do and learned what I liked.) about my breakup because of the central thought that I’m not valuable, therefore not valued. I know I need to get to know myself and develop a relationship and love for myself before I can show up as my true self FOR myself, or in any relationship. I know it’s a journey. How can I take deliberate steps to show up for myself?