Boy troubles

Okay so I'm not sure if anyone will actually read this or actually care but I definitely need to vent.

It seems like relationships never work for me. I'm always loyal, I go out of my way for my significant other, but in return I end up getting my heart broken. I'm to the point where I don't ever want a single relationship again because of how shitty I've been done. I just hate that I always give 110% & get nothing but a broken heart.

Advice? Comments? How should I handle dating & relationships.