RE: HELP! My horse NEVER comes to me
I agree with the others. Do lots of binding, grooming, leading, etc. Make his time with you relaxed and fun and he will want to come to you.
Have him checked by the vet. Maybe something is hurting him when you ride and so he tries to avoid the situation.
Make sure everything you do is calm and soothing. Don't yank or get angry or frustrated as this will make him tense and edgy. Be kind and gentle and respectful of him.
One thing that works well with my young Dartmoor pony is to go in the field with a stick (like a parelli stick, although I have used an electric fence pole when I was desperate). Wander around the field, don't go towards him, just wander about with no agenda. Sing or whistle to your self, keep tugning around and walking in circles. Stop occasionally and inspect something on the floor or fence/hedge, etc. It sounds mad but it will take your horse off guard. He won't be thinking 'she's here, she's going to catch me', he'll now be thinking 'what on earth is she doing?'. Keep an eye on him. What you want is him either ignoring you or showing an interest. If he's still looking like he'll run off everytime you go closer then keep wandering til he's relaxed.
Then go as near to him as you can get without him running away and hold the stick towards him (obviously, if he's stick phobic then use a different implement here). As soon as he turns towards it or stretches him nose towards it, pull it back towards you. Show him it's interesting and will retreat. He should react quicker next time you hold it out. My Dartmoor is hugely curious and can't resist wandering closer when I do this advance/retreat stuff.
Edge closer as you're doing it and hold the stick closer to its end so you are getting closer as well. Then do the same with your hand. When you can give him a pat or rub on the next, finish there and walk away.
He will be totally confused, but it will have been a different and pleasant experience for him. This should help change him outlook towards you in future times. You'll have to repeat this exercise and you will look like a crazy person, but your horse will benefit.