Help - I'm Остаться в живых

I have never seen a first run DH. I started watching the reruns on Lifetime network about a месяц назад when they started with episode #1. The reruns were in season 2 или 3 when all of a sudden they jumped to the beginning of season 6. My only hope to get back to where I was is to buy the DVD's for each season but I don't know where I was when they left off. The plot where I Остаться в живых it: Edie just burned down Susan's house; Susan got Edie to confess on tape; Edie got stung by the bees and she is in the hospital all puffed up; Carl is up to no good because he saw Mike buying and engagement ring for Susan and Carl bought Susan a new house.
Please tell me where I am at so I can buy the DVD's and get started again. The reruns on Lifetime make no sense to me at the beginning of season 6. Thank you.