When you begin, start with One Bag to give to a friend or swap; and about 4 Bags to donate to Goodwill, Salvation Army, or a local Church group. And One Bag to Sell. And train your mind: have affirmations (mantras) to soothe your soul as you work, such as:
* "I've Loved this fabric/pattern for X many years; now it is someone else's turn."
* "I haven't brought this kit/pattern to its full potential; so I will sell it, and use that money to complete a project I have begun."
* "I know someone else needs this piece; I just have to offer it up."
Affirmations like that kept me sane while I 'dematerialized' before my big out-of-state move last year. You can do it. Put energizing music on to keep your spirit up.