What's hard is feeling complete making a dinner for one. What's hard is not getting the effort back you're putting in and walking away instead of trying harder for someone who, sadly, isn't trying for you. What's hard is feeling lonely, unwanted, and tired but still confidently knowing that it isn't you.
I'm not writing this to give you some false sense of fairytale. What we all need, lonely or not, is a sense of security and contentment with being alone. Your relationship status has no effect on your ability to have singular worth. It is possible to be happily alone; unfortunately, the word alone has a bad aftertaste because of self and societal expectations and views of what happy looks like. The good news is that luckily you have all the say in what you do and what you find fulfillment in. Although it's not easy, fulfillment can be found in yourself. Your life can be written where you're the main character and also the only one that's consistent throughout the entire story. Don't forget, some of the very best stories aren't love stories at all.