am i cursed for relation ships?

You answered your own question, I think. You said your relationships break up because of "certain things you do." Then stop doing these "certain things". Sometimes it's how we liv our lives. I know of one man who thought he had bad luck, because he was always in trouble, and al his friends and assciates dies. It was John Dillinger! If he had lived his life different he wouldn't have had "bad luck".

I don't know what the "certain thing" is, but you may be able to find help on the link below.

That's a bit young to believe you are cursed, at that age you are just beginning to learn a little about what makes a relationship work. Give yourself 40 more years of learning and then come back here if you still are unlucky in love.