Love is strange...I suggest doing your best to evoke such strong feelings for/towards yourself. Maybe she's the one, maybe you haven't found the one, but one thing is always certain, once you feel completely content and happy being single, someone will come along. Once you finally feel free of the longing for romantic love, someone comes along, inspired, and wanting to enjoy you.
I truly understand the pain of having loved then lost love. It's important to be true to yourself and honest to others, don't leave room for regret. Most of all its important to express yourself, this post was perfect, if you feel your emotions are still bottled up let them out. I'm sorry her sister, of all people, ruined things, it wasn't her relationship to interfere so much but it's a reminder that, unfortunatlely, sometimes families get in the way and there's only so much you can do in such situations.
I'm inspired by your emotional expression . It's something people forget to do, something people need to do.