Most Helpful Girl
Honestly, it depends on the person. I myself get attracted to looks first, then their personality determines if I'm further attracted to them or if it pushes me away. My best friend on the other hand is attracted to personality primarily and is attracted to their looks because of their personality. She introduced me to a guy. I knew physically he wasn't my type, but as nice as he was, his personality just wasn't my type. It was hard to be attracted to him.
Keep in mind that just because you are sweet and nice, it doesn't mean you're going to attract everyone. Everyone has different tastes, personality included. Some girls like the mysterious, sensitive types, some like the very outgoing types, some like the shy guys. In other words, just because you're sweet and nice, it doesn't mean she'll automatically be attracted to you even if she doesn't care about looks. This isn't saying to stop being nice, lol, you just have to meet someone who just likes your personality.
I know a guy who is rude and it just annoys me (I don't know if he knows, but he makes people feel like crap for the things they enjoy). If he was lot nicer, then I would see the appeal of him dating, regardless of his looks. So, being nice does pay off, but your personality may not be for everyone.
Another thing is do you truly think you're ugly? How you perceive yourself may be the thing holding you back. If you keep complaining that you're ugly and no one wants you, it's kind of a turn off. Just try to be comfortable in your own skin.