Don't give up. My riding instructor injured his back, and he's telling me what to do to get my horse trained.
Yes, my horse is NOT trained yet, and my instructor is having back problems. I've been frustrated to the point of wanting to sell my horse and getting a more experienced one, but I stuck to what he was saying, and guess what? We're competing in two weeks! When I brought my horse to the stables last year, I couldn't ride him without someone leading him... I didn't have control. But now im able to get him to take the bit and I'm training him to gait (He's a Tennessee Walking Horse), and I'm riding on my own. He's 5. Yeah, a little late to be training him, eh? Well, Yeah, that's what I thought, too. My trainer/instructor told me what I had to work on for the week, (getting him to take the bit) And now Bridling is easy! So even though you're instructor is unable to show you what to do, or even able to get to the stables, that doesn't mean she can't help you. Get her number, and if you're having any problems, call her and tell her your problem, and ask her what you can do to fix it, or ask her what you should work on that week.
Theres no need to sell your best friend, and quit doing what you love. Just keep riding, and ask her any questions.