Well, being in love currently, I can sorta field some of this.
1. If you're in love with someone, but are dating someone else, something is wrong with you. Relationships like that don't really work. If it really is love, and not some other emotion you're confusing with love, you don't just "get over" it. If it really is love, and you're in a relationship with someone else, you have a few options.
A: Ignore it. If it's love, you can't really ignore it at all, but you can treat your current relationship differently, and pretend that it doesn't matter that you're in love. Treat your current fling as a more friendly relationship, maybe even friends with benefits, but make it clear that you don't see the relationship getting too serious, and keep it like that.
B: If you're already in a serious relationship, you should probably call it off, cause apparently it isn't that serious if you just fall in love with someone else. Break it off, and tell the other person that you just don't see the relationship going any further, or that you don't think it's fair to be in a relationship with someone, but have feelings developing for someone else. Don't lie.
C: Threesome. Or at least try for it. Some partners are totally cool with that.
2. If you try to get over the person you're in love with, and it's not working, then maybe it really is love. If that's the case, you're sorta dicked. If you really love someone, you're not just going to stop. The only hope you have is time. These things get better to handle in time. You might never stop loving that person, but you learn to live with it, and can come to accept the possibility of being able to love someone else as well. This really works best if you're not around the first person you fell in love with, so if at all possible, try to avoid contact with said person. If that doesn't work, spend tons of time with them instead, cause then either you'll hit it off with the person and have a serious relationship, or you'll get to know them better and realize that you're not meant for each other.
3. If you want to let the other person know how you feel, you first have to gauge the waters. Most people run from others they don't know very well saying something like that to them. If you already know the person well enough to have casual conversation with them without it being a big deal, then go ahead and tell them that you're interested in them, or just come out and ask them on a date. Letters really don't work well here, and the last thing you want to do is email. Talking to the other person is best. And most people are attracted to confidence, so build yourself up before trying to talk to them. Say what you mean, and fuck whether she responds well or not. You don't need her. At least, that's what you should be telling yourself, regardless of if it's true or not.
