Only people who haven't really lost someone say this kinda stuff. The pain of loss eclipses all the good parts of having loved by a large margin, in my experience.
Again, spoken like someone who hasn't lost someone. You may become progressively less likely to let any given person become that important to you over time, but losing someone truly important really doesn't get easier.
I've lost more than one someone over the years. To be honest, the most important thing is being happy with yourself, whether you're in a relationship or not.