I can only suggest losing the choke chain, it isn't working. Have a trainer fit a prong collar on your girl. And get a basket muzzle.
The first step is management. You have to protect everyone else so that your dog remains safe. So 100% on lead, basket muzzle and prong collar to keep your dog from dragging you into what she is fearing or aggressing towards.
In my opinion, training is a big part of the picture, but management is first. Leadership is also a big component, and exercise. The treats and desensitizing your dog to what it fears or aggresses toward is important, but first the dog has to trust you. It has to accept and understand you.
Just because a dog is ok with us, does not mean they believe we will protect them. And it doesn't mean that they understand our communication. A good place to start is NILIF -- Nothing In Life Is Free -- lots of stuff on the net about it. When you enforce proper leadership, your dog should become more comfortable with you in all situations.
Management before you take your dog out again. Leadership is a process that you must learn with your dog. It will take some time to read through everything and implement with everyone in your household. While you are working on the improved leadership, continue to train the dog. Stay away from distractions for now. Try to build a bond through training. Lots of praise and treats should help, but clear negative markers are also important. Your dog needs to understand that there are consequences for correct and incorrect behavior.
Of course you will want to exercise your dog several times a day. And if possible in a fenced yard, where you can let your dog run and chase a ball, and work on basic training routines with and without leads. Exercise body and mind, a tired dog is a good dog.
Lastly, the careful socialization and desensitizing the dog, once you see a marked change in your dog due to the change in leadership style and you have marked improvement in training without distractions, then slowly, a little is a lot, start adding in a session with the distractions. Try to start far away at first, and try to stay below her threshold. Over time, weeks, maybe months, start getting closer to the problems, and learn your dog's body language, at minor stress adjust your pattern of walking to put a little more distance between you and what stresses her.
Eventually, she needs to learn to deal with stress, but that will be easier if she has a confident leader that she understands, and has a training bond with.
Management -- prong, muzzle, 100% on leash or in fenced yard with you
Leadership -- NILIF
Training -- build a bond with positive praise/treats, and clear negative corrections -- EH!
Exercise -- body and mind
Careful Socialization/Desensitizing -- take your time, she didn't get like this overnight, and she won't stop overnight.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC
Hepzibah & Hannah