Question, do you prefer to be single or in a relationship? What are some pro and cons of being single/involved

I am currently in a relationship but it seems that the gr is always greener on the other side. Why is this? When I'm single, I want a special someone. When I have a special someone, I would rather be alone and just go and come as I please, not answer if I don't want and things like that. I always feel confused and indecisive. And I notice that I have a short attention span as well. I like a guy only for a short period of time and then I start to feel like, okay enough with him. Next!