Am I past repair? Please answer!?

[kat]

Last year I was a confident rider, who loved horses and had an amazing bond with an ex.race horse, thoroughbred mare named Symone. I would do almost anything in the saddle with this mare, and my mom was planning on buying her for me, but we were going to wait till after the horse show I entered to buy her. I'm glad we waited. Her being a racehorse earlier in life should have been my first clue she wouldn't be safe for me. I was riding around with some other girls in the arena before the show started, and one of the girls came galloping up behind Symone, and she thought she was in a race. I held her back and so she turned into a bucking bronco. The last thing I remember was seeing someone pull the metal gate back so I didn't hit my head off of it when I was falling, and feeling my body twist through the dirt. I went to the hospital in an ambulance, they thought my spine was broken. It turned out I had badly bruised bones in my neck, legs and arms, and a bad concussion. I didn't get back in the saddle until 6 months later when my mom brought home a new horse, named Tia. Tia was abused so badly before that she didnt trust people. Mom forced me on her, and Tia didn't like me up there. She would bolt if I didn't constantly be holding her back, and she would lunge to bite me whenever I was around. I tried hard to bond with her but she just doesn't like me. a year later and she still hates me. This made me even more terrified to ride at the horse show mom was forcing me to do. I was shaking I was so scared, and I cried during every class I wanted out of the saddle so bad. Mom pushed me. It made it worse. Since I was so scared during the show I was projecting it to Tia, but I couldn't help it. All 3 of my classes were hell. I almost fell off of her at least twice in each one.
I'm not a good rider anymore, I will admit that. I love horses and I want to ride again so bad. When I go to sleep at night I dream of riding my new mare named Dancer ( She is my profile picture) but when I go out there and try to ride, I can't do it. I shake, I cry and I know if I get on it will only make things worse because I will scare the horse. I have had a trainer to help me, but whenever she comes out my mom tells her to push me, and I can't convince them that I am too scared to do it. I can't tell my mom how I feel because she has some kind of anger issue and it all blows up in my face.
Its gotten to the point where the only horse I can get on and ride is my old gelding who has arthritis so he can only walk under saddle ( The vet said he is okay to ride under saddle if we only lightly walk him and for a short time) I can only trust him because I know he won't bolt or buck me off because of this.
But when I ride him, even though its only a slow walk, I feel so alive, and good.

Why can't I get back on a different horse? I really want to, so bad, but I can't have someone help me do it. My mother won't allow me to go to a trainer who can start over with me. I don't know why.
I'm afraid I will never ride again, and imagine how badly that would hurt, to not be able to ride a horse ever again.
I just don't understand how I can be so in love with it, and wanting to do it, but I can't get back up. I don't want to be in fear of riding. Any tips or own expieriences or anything to help me is great. Please no hate, I know this question is all over the place and quite long, but it would mean so much if you can give me tips on how to get back on comfortably. Thank you.

I will probably be replying to answers that were rude or need further explaining on my part in the additional details as well.

Thanks c:
The Christ puncher: I know you're trying to sound cool and all, but the whole reason for this question is that I can't "Suck it up" .
I cannot team up with Tia. I've tried, but putting us together stresses us both out.
I have a horse of my own named Dancer who is actually my picture thing on this, but she is only green broke.
I've gotten a lot of really amazing answers from you guys...Some have asked for private messaging but unfortunately I don't know this site really well enough to do that, so you can e-mail one of my e-mail accounts to help me further if you want (: danielle-obrien@hotmail.ca