LoA is nothing you can make work by investing time in it. You think all day long. What does it matter, if you think the right thoughts for an hour and the rest of your waking hours, you wonder if is working or stuff like that? LoA doesn't only work on small things, but you don't sit hours to meditate about the small things, do you? So you do things differently. How can you expect the same results?

You can't "stop" anything with LoA, because the moment you want to stop something, you focus on it and by doing so, you attract it. You could still attract him to be your partner, but if this is worth the effort is something you have to decide. If you see a chance to be happy with another person, that would be the easier way.

You ask, if you wasted your time. Well, that's the problem here. You didn't do it, because it felt good, but because you wanted something out of it. LoA doesn't work that way. There is nobody sitting on a cloud and measuring how much effort you put in. You always get what you feel. As long as you feel that he is not in your life and that you have to put effort in, he will stay out of your life and it will feel like even more efforting.