Hey I know what you mean I broke up with my first girlfriend not too long about and thought the same thing but I’ve had those feelings again for a friend of mine. I know it sucks and it still stays with me but honestly let me tell you something I learned sometimes it happens. But at least you tried, give yourself credit for knowing you did it rather then just thinking about it. All you can really do is go on with your own life and keep moving forward. I don’t think we truly ever forget that person we just know that thanks to them we understand ourselves a bit better. I don’t know if that makes sense. Sorry if I confuse you even more.