These are your problems with the untenable doctrine of sola scriptura. If you have an extra-biblical source to tell you which books are inspired, you avoid these logical difficulties.
Which there is ... the Holy Spirit.John 14:25 These things have I spoken unto you, being yet present with you.Do you deny that this is the case ?
26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
Which there is ... the Holy Spirit.
If the HS has given you a revelation telling you which books are inspired, I think you should share that with us.