Horses use body language as their main form of communication. Ears are a part of the body, and therefore can be used for communication. It's called "body language" - not "ear language". You have to look, listen, and read the entire horse; do not take something out of context. Ears back and ears flatly pinned are two very different things. For most horses, simply having their ears back is not really enough to warrant doing anything. The horse could be listening to something behind them, relaxing, standing in the wind, or in pain.
I do not understand what you mean by "try[ing] to jump on me." Do you mean the horse is moving forward and you just so happen to be in the way or that the horse is literally jumping on top of you, as in attacking? Perhaps you could clarify?
The trick is to move the halters around to scare the horse
Unless the horse is being extremely aggressive and/or trying to kill you, for most of the time, you should not be trying to purposefully scare the horse as a form of correction. The purpose is to redirect and teach the horse - not scare them; a horse cannot both respect and fear you.
I’m trying to be the most gentle possible
While it's good that you are trying to be gentle, if it's not working, then it's not working. Do not do the same thing over and over again and expect the horse to give you a different result. You either need to change the question, change the way you ask the question, or change the amount of pressure. "If the horse gives you the wrong answer, it means you asked the question wrong, for horses are (usually) a reflection of how they are handled." Set the horse up for success (not failure) and help them find the right answer.
this horse just don’t like me or like to go to the lessons.
Is this a lesson horse? Many lesson horses tend to be jaded, especially if they are teaching beginners, especially, especially if those said beginners only go out there and work the horse.
Another problem is when putting the saddle, always ears on his back and try to bite me.
This goes back to my previous comment. How is his health? Horses that are in pain, such as from ulcers, can get girthy. How does his tack fit? Ill fitting tack can be uncomfortable, and in more extreme cases or with sensitive horses, cause pain. How do you ride? If you're unbalanced, flopping, and bouncing around or ride like sack of potatoes, that can cause the horse's back to become sore, especially if coupled with ill fitting tack.
Has he had this problem before? If not, then it is likely to have been caused by one (or some) of the above factors or something else. If he has had this problem before, it could be because he never learned to accept that being girthed is okay.
What do you do when he tries to bite you? If you flinch and yield, that is basically teaching the horse that biting, or the attempt of, is the right answer. If you do so, the more you do it, the lesson gets reaffirmed every time, and the behavior will be more difficult to adjust later on. If you correct sometimes and yield other times, that confuses the horse about whether or not biting, or the attempt of, is okay or not. Once you set your rules, you have to be consistent.
Do not be quick to blame the horse. Examine the above and get back to us.