Late last night i noticed my JRT had a split/broken toe nail on her hind foot. I have absolutely no idea how she done it. She is very bouncy and full of joy so i'm guessing she's done something daft in the garden. My worry is getting her to the vets as she is absolutely terrified. I got her as a rescue about two years ago and when she had her boosters last year she had to be sedated as no one could get near her. She was too strong and wriggly for anyone to hold. Her other issue is her feet!!!! To trim her toe nails/dew claws normally takes me about two hours as she hates them being touched or even stroked. I have to get her in a totally relaxed mode and hand out plenty of rewards. By taking her to the vets am i going to reinforce her fear of the vet and feet being touched or will her toe nail heal in it's own time. 
When i got her as a rescue i can't emphasise enough at how badly she had been treated before she came here. I couldn't get within 5 feet of her for about two weeks as she would just run away and cower in the corner. I feel like i'm stuck between a rock and a hard place!
Any advice would be greatly appreciated. Thank you for reading.

Can't advise on the nail without seeing it, sometimes they are OK, but it depends on the damage - really your vet might be best this time - a split can be more painful than losing the nail.  

>Her other issue is her feet!!!! To trim her toe nails/dew claws normally takes me about two hours as she hates them being >touched or even stroked. I have to get her in a totally relaxed mode and hand out plenty of rewards

Sounds like you have the right idea here - but if you did this daily with the rewards ;) and not just when you want to trim her nails, she will learn that having her feet massaged is a relaxing and pleasant experience.  Then when you have to do nails it won't be such a big deal ;) and if she ever has a problem with her feet she'll trust you enough to at least check :)

You've come so far with her, I'm sure you have the patience for this and your relationship will benefit so much :)