It is normal for a young horse to feel a little bit confused the first times he jumps.
First of all, make sure your horse doesn't have any pain that might cause him to act like this.
Then, when you're sure he is in great shape, try to free jump him. Start with very small fences and do ask him to much during the first sessions. Reward him every time he behaves good.
When he feels great on free jumps, you can ask the same in the saddle. Do very easy and small jumps to give him more confidence.
I'm sure with that with patience and treats you will give hime more confidence.
Good luck :)