"I would rather be lonely alone than with someone."

I used to say much the same thing. Loneliness when you are with someone sho just can;t be arsed is keener than loneliness alone. Kind of a constant reminder that you are lonely.

In fact I believe, if I had not met my current love that I would not feel lonely.   If I wasn't so blasted contented (I am like a pampered cat) in my current relationship, I'd rather relish the idea of solitude.