I love my brother's wife. She is my soulmate in my eyes (non-sexual). I feel bad, how do I hide this love from him and her?
Move away, and get your own life, pronto. What you are doing is stalking, and nothing good is come out of that. You certainly aren't going to win her over.
"I intentionally drive past their house just to see her through the window. I do this every evening." You ARE stalking your brother's wife - and there is no way that is healthy. Such behavoiur will get your "secret" uncovered in time. You need to stop this behaviour - seek professional help if you can't. I suspect you are focusing on her as the "unobtainable" so you don't have to face the fact you have so little else in your life. Change focus and you may well change that too. If it was real love you would want what is best for her - and she chooses your brother to share her life with. IF you respect her, you respect her choice and leave her alone. Anything else is selfishness, and that is not the behaviour of a soul mate at all.
You need to slap yourself and get over this obsession dude. It’s good that you haven’t acted on it yet. But she obviously doesn’t feel the same way. This can’t end well if you keep up the obsession
pit bulls bite
move further away
Don't you feel sorry for their children? I think you'd be better change your mind.