Women New Korean Loose Hooded Sweater Coat Of Irregular Length Knit

I was looking for an over sized sweater, this lookef perfect. I am a size large, I ordered a 3X, it fits like a large. I can wear it but the sleeves are short, have to keep them pushed up or have 3 inches of arm showing.

So I got it in the mail. Tried it on and the sleeves were very short. I hung it up in my closet and figured I would give it to my niece for christmas and I went to show my husband a week later and I showed him how it fit and it seems to have stretched out. The main part I didn't like was the sleeves and questioned it but it ended up working after hanging awhile it did stretch out to fit right. Now to figure out how to wash it with out shrinking it.