Feeling SOOO guilty

Gosh I'm feeling guilty tonight. I feel as though I caused a chain of events that in the long run hurt someone that I really care about. I never thought that what happened for me to "cause" this would have happened, nor did I realise that because of what happened, which was good, a blessing, would come such hurt from someone else to someone else. Ug I hate being vague, but I don't think its fair for me to talk about others behind their backs, when, even though it severly upsets me, its not really my buisness. Even though I feel like I caused it! :( It makes me physically ill.