There's two ways of looking at it, Sophia, from what you tell me.
Maybe your instincts about his laziness and slight selfishness will grow over time as you get to know him better and in that case I would say follow your instincts and this clearly isn't the right bloke for you
But on the other hand if he realises that some of his ways are not cutting the mustard with you he may improve them and become a more worthwhile partner over time if you mean enough to him
Only you can find out the answer to that one
As to being confused and afraid I just think that is part of the love package. I guess this is because we find ourselves in the grip of emotions that take control of us and that can feel pretty overwhelming, but that applies whether you are falling in love for the first time or the second time and beyond, though I guess it can be scarier if you have never felt this way before.
In any case give yourself time. You are young, what's the hurry..?