How do I get over being scared of a relationship?

three years ago I was in a relationship I was extremely invested in emotionally... She dumped me out of the blue on a holiday whilst surrounded by a large group of people. I raged off and was so hurt I couldn't help but want to hit something.. I ended up with two broken hands and I haven't dated since. Now I found someone I really truly care about again but im so terrified of letting her know who I really am in every way you could think. I don't want to sabotage a good thing but im so scared of getting owned again what can I do to stop this kind of thinking