"Are you saying I'm mentally unstable?"

It seems like everytime someone tries to get close to me I push them away, by testing their bounds. I try to see how far I can push them until they finally crack, & break. I say and do the craziest things just to get a reaction. I believe this is why I will never be in a healthy relationship again. Atleast until I stop this, I just have a hard time setting my gaurds down. After I got my heart broken for the first time I never wanted to go through it again, so I'm not allowing myself to get in too deep. It seems I can only show my true feelings to my friends and family. Anyone I see as potentially more than a friend I put my walls up, I don't give a chance, I break hearts. But when I go to bed it's a horrible feeling being completly alone.