I find in most things in life belief that you can comes before the success. I'll use a personal example..
I want to be someone who is athletic, health conscious, and successful at a small business. Those are my goals right now, so far I have started and stopped, and repeat. What at least for me is holding me back from attaining the results I want to see is lack of belief that I can succeed at them. That belief wavers a bit, so does success right along with it. Sometimes stronger, and then less so.

Alot of my lack of belief stems from fear. Even fear of being successful. Hard one to get at the root of. My fears make it very hard to see the outcome that I want.

Maybe taking a good looking and trying to figure out what the root of that fear is will help you confront and challenge it. For me it's a bit of a slow process, slower than I'd like but then I also admit that I have not given it all the effort and focus that I can. I am holding myself back and getting in my own way.

Not sure if you feel this would apply to you as well. But I have felt that way in love as well before too.

I hope you can let go of the fear, I believe you can find what you seek. I hope you will find what you desire.