I'm three weeks out on purée. Every time I eat it feels like its stuck and hurts going down

Does every bite hurt, or does it start hurting before you finish your recommended portion?

If every bite hurts, you may need to drop back to the full liquids stage for a day or two. It's possible that the swelling in your sleeve hasn't gone down enough to have pureed food yet. If it hurts to finish your recommended portion, you may not be able to eat a full portion yet. Try taking a bite or two, then wait a bit to eat more.

A call to your doctor won't hurt anything, either.

It hurts after a bit or two and feels stuck in the middle

I still think you should call your doctor, and go back to full liquids for a day or two. If it hurts, that's a sign that you're not ready for puree foods, and your doctor can make sure that's all it is.