I love someone and can’t stop thinking about her, but I also know that she hates me and will never consider going out with me because of a horrible fight we had when we were in college together. I wish I could erase what happened, but I can’t go back in time. All I can do is hope that she changes her mind, but that can’t happen if she won’t even consider letting me into her life as a friend. What can I do to make this happen? I know what happened back then was a mistake, but it feels as if she is still stuck in the past and incapable of seeing how I have grown or what I’m really like as a person.
You can try writing to her and explaining what you think has changed. If you have caused pain, it is her prerogative to decide whether or not to let you into her life, but a change of heart is impossible without establishing a line of communication. If she isn’t going to speak with you, try putting across your point of view in writing. If you have common friends, you can consider asking one of them to mediate. All of this is irrelevant if she isn’t willing to forgive and forget though, so it’s important to acknowledge and accept that this situation may never resolve itself. She may choose to not have anything to do with you again.

My ex-boyfriend recently messaged me to say that he still has feelings for me and wants me to give him another chance. I am confused because I miss him, but I know why we ended our relationship and don’t want to put myself through that again. What should I do?
Just meet for coffee. If you are confused, ask for time and think about taking things slowly. Neither of you has to commit to a relationship again, so try taking small steps and seeing how things have changed in the way you engage with each other.