if you think you can't be happy unless you're not alone, I can almost guarantee that even when you're with somebody, you'll still be unhappy and still feel alone. Your best way forward is to learn how to be happy and alone.
If you're someone who's in a will-they/won't they kind of situation or someone who's in an on-again/off-again, up-and-down relationship, and you're wondering if you should give up or keep fighting, you might need some help.