Problems leaving home (me, not the horse)

Ever since I began taking lessons this fall, my confidence has improved SO much. I'm not sure how much that's saying, seeing as I had zero confidence before, but I still feel like a much, much stronger rider.

No matter what, though, it seems like I just can't get over my fear with my horse. I just want to clarify, it's only THIS horse. Any other horse I ride, I'm totally fine. I'm totally confident. But my past with my horse has just conditioned me to be nervous riding her.

Which is the weirdest thing, because nothing bad has ever happened to me on her. She's done some scary stuff (terrifying to me, as I was a total beginner, probably a *yawn* 'Wow, that was rather ignorant of you* deal for someone else), but I've never gotten hurt and never even come close.

My trainer (who also broke this horse) said: "I don't understand why you don't trust her. I always thought the world of this mare." Because my horse is amazing. It's just that I'm not.

I can trailer her away anywhere, pull her off, saddle her up, get on and go ride without a twinge of fear. But when I ride her around or directly from my home property, I just..can't. That's the most frustrating thing ever. I don't know why I can ride her in new, totally strange and scary places but I can't ride her in a familiar environment without my nerves playing in.

When I 'hack' her out from home, my mind is constantly on home. I'm: ':shock: We're leaving home. She's going to get nervous because we're so far away from home. What if she tries to pull for home? What if she wants to run home? Maybe we should go home soon." And because I'm constantly thinking about and worried about home because I think the horse will be, then naturally, my horse starts worrying too, even though she's not barn sour, she really couldn't care less about leaving the other horses and she's not a naturally spooky or nervous horse. She never throws tantrums, she never spooks big, she never does anything bad, I just FEEL like it's way, way, way, way worse than it ever is. It's just a toxic mess of emotion that I start. My trainer has told me that I never ever LOOK unconfident; I ride really..well, confidently. All this uncertainty is in my head.

I think part of the reason I can ride her so effectively trailering away is because not only are we nowhere near home and the barn, but whenever we do that, there's always someone there riding with me, and there's always something to do. I really wish I had someone to ride with me at home, but my friend I usually go with, though she's a good rider with more years under her belt than me, isn't a terribly enthusiastic rider. I'm lucky if I can get her out once a month. Twice is way too much to hope for. Which isn't much help for me, who wants to ride every day.

So I guess that leaves me with trying to find something to do to keep my mind busy and off of home and my horse acting up. What sorts of things or activities can I do off the property while trail riding that you think might help keep me occupied on the task, not my horse or any possible pulse she might have ?

Also, do you think getting out more, as in trailering away, and riding her a whole lot out there (even though I'm not scared in those environments) will help with riding at home?

And I know it's probably crossing a lot of your minds right now, but please, I don't want to hear people telling me I should sell her. Not because 'She's my best friend and I love her more than anything in the world!!! You guys are mean poopy heads and you don't understand the bond we have!' It's because I want to try. I know I've been trying for several years now and I'm not 100%, but as long as we continue to progress, I'm going to keep going with her. My trainer has said that she'll bring me riding a lot this summer, she'll take me camping - all that jazz, to try to teach me to finally trust this horse.
I just don't want to give up. I don't want to fail. I want to conquer this long, incredibly difficult obstacle and beat my fear. I won't run away from it.