I don't think you really discouraged it, jumping on your back shouldn't be acceptable so I think you did the right thing by getting up. A lot of dogs aren't as cuddly when they are puppies, they are more interested in play and romping. Of the 4 dogs I've had, 3 got more cuddly after they got older, after age 3 and even more around age 5. Tommy is the exception, having always been an incredibly cuddly dog. Willie was never as cuddly as Cody, he'd lay by me, get his cuddles, and when he was satisfied he'd go lay in one of his sleeping spots.

If you'd like to encourage cuddliness, perhaps keep some little treat tidbits on you, and then when he sits or lays quietly by you just letting you pet him, slip him a treat, eventually him learning that sitting/laying quietly is good behavior.