In my experience, fear aggressive dogs are the most volatile and most likely to bite. Staying your dog’s alpha leader is key in squashing this behavior. Also very important is to project a calm vibe, as your dog will feed off of your energy. So, if in anticipation you are not relaxed, your dog will sense this, and react with her instincts.
I am currently training a spayed 5 year old weimaraner who is a rescue dog. She has responded well to desensitization training, although her progress was slow at first. I find it helpful to take her for short walks purposely along routes where we are likely to walk past dogs in fenced in yards, and over time she slowly learned the threat was contained and not an imminent danger to us. From there I up’d the ante and placed in situations where face to face encounters with other dogs were likely. Each time you increase the exposure level remember to always stay relaxed and in control. Slow progress is best, and over time she will make you proud.
During this process I have taught her a command which when she hears it she knows it’s off limits. You’ll have to find a command that works for you, and use it only in this type of situation to guarantee quick recognition and follow through.
It may also be helpful to as @Darkscribe mentions, find a buddy for her to explore the world with. I
usually try to introduce dogs this way, by taking them for walks and hikes together. I would however, not recommend tethering your dog with another one until they have spent some peaceable time together, and if they are of somewhat equal stamina and character.