Dazzled

I never knew that something ordinary for me is actually hurting someone, but that something is very common to me..I can't just threw it out....i'm so confused by now..what should I do?I don't like the fact that someone dear to me is hurt by my common life...but...I don't like the thought that I threw away a friend just like that, well they had a good will to be friendly and if I just toss it out...I believe in law of karma..It would be mean I too will be tossed out someday...well something like that.....confused is it had to be like this? that if we WAS like someone then now we should never had any contacts what so ever again with them?