Well first off I have no idea how old you are and if you really know what love is so it is hard to say if what you are feeling is really love or just like or infatuation etc. Now that being said I don't think that there is just one person in the world that you can love. What are the chances that most people grow up in the same town as their one true love really? I think there are many people in the world that you can love and be completely happy with. Just because you love one person does not mean you can't love somebody else. I do think that you have to make a decision because what ever you put your time and effort into is what you will want.
I don't know.. it may depends on his behaviour, the way he treated you and the time you spent together.. if you feel that something changed on your relationship that means it wasn't the right guy for you and that's why you let yourself love someone else! it may means that you've been hurt and the second guy helped you escape for a lil bit.. but that doesn't mean that you didn't truly love the first one! But it also may means that you're too young (i don't know how old are you) to say that you truly loved someone.. it's difficult to say something like that in a young age.. it may was just a crush and you got over it! :)
I would say probably, but how old are you? and do you really know what love is? I got married at 19 and thought I knew what love was.... and honestly I didn't have a clue until I met my BF that I have now - I never felt this way about my Ex husband. Did I love him, well I certainly thought I did when I was 19, but back then I don't think I had a clue what love really was. I am totally in love now and would heaven and earth for my man now :)