Most Helpful Girl
Yes, you should be heartbroken. This was your first relationship. You gave this b*tch valuable, precious, divine energy and time alive that you can never retrieve. Therefore, it's going to heart.
Just don't go back to her. She's a piece of sh*t and you can NEVER trust a cheater. Don't try to be friends: delete and block her from everywhere. Feel positive knowing that she will never be able to rob you of your peace and joy again because she's out of your life.
Most Helpful Guy
Think of it this way; a part of her is clearly not happy with your relationship and hence why she cheated. That simply means that you're not the right guy for her ya know. I've been cheated on many times, and I actually don't feel any more emotional destruction right after a break up. You and her are simply not right for one another and if you truly care about her, you have to let her go any how. You've got to move on and forget about what could've or shoulda been. Don't blame yourself because in this case, it's really her and not you. Good luck mate.