I think that the first thing you need to do is start talking to her again. Just as people, not as friends, or lovers, just as human beings.
Once you start talking to her and you feel comfortable (could be a day, maybe two), it will be a lot easier on you and her to tell her how you feel.
As for the should i apologize or not part, it all depends on who you are. If you are someone who is truly sorry and wouldn't be able to go on without telling them, then i think that will come naturally in your conversation when you are telling her that you like her.
If it doesn't feel right, then don't apologize, but it should come naturally.
Don't like jump out of a bush and scream "i love you and i miss you" she will never look at you again. You need to work you way up to the telling her that you like her. I honestly think that you should tell her that you still have feelings for her and that you missed it when you two didn't talk. If i were you, i wouldn't tell her that you love her. that should come later in the relationship
If you have anymore questions just ask and anybody can answer them for you. OR if it is a little bit more private you can PM me like numerous people have already