This is and OCD issue. I have a hard time with unloading items. I am a pack rat and my husband usually has to pry things from my hands to get rid of it. This causes me much anxiety. I have always been this way and I really do not see an end in sight. I keep old magazines, old receipts, old envelopes, and other meaningless things that should be thrown away. As far as the clothes issue go, I have gotten alot better with this. I hand my old clothes down to my younger sister who is 16. My girls older clothes, I hand down to my best friends daughter and my sons clothes I habd to my husbands friends son. By handing the clothes off to another, I dont feel like I am "throwing" it away. I feel like I am actually helping someone out. We all know how expensive clothes are these days. LOL. It takes time to feel comfortable with letting go. Like I said, I still have alot of anxiety when it comes to throwing things away.
Maybe if you tackle one corner of a room at a time this could help, doing it little by little. I dunno. Dont be to hard on yourself.