Question about my dog and her?

separation anxiety problem, i put her in her kennel yesterday with her chewing toy and blanket and tv on. i walked around the block and wen i came back i heard her a few houses away she sounded like she was getting hit by a car. i spoke with my neighbor lady and asked her if she acted like this before and she said yes! and i had the door and windows down yesterday due to it being cold outside. she must have been really loud in the summer with the windows up. i apologized and told her that i would be working with my dog on the anxiety wen we leave. this isn't the only anxiety problem that i see with roxy she whines and goe,s back and forth to the windows of the backseat of my car she walks all over the kids in the back seat i take a Spray bottle of water which she hates to get misted on her, shes been thu puppy training cles wen she was 5 months old shes 11 months right now we got her wen she was 3 months old someone found her and couldn't keep her so we took her in shes pit bull mixed with something else but the vets said that she probably is 90% pit shes a hand full she was bullheaded about potty training chewed both mine and my husbands inside our car interior we cant leave her in our house are our backyard alone because she chewed are back screen apart our back house siding and anytime we leave our door she screams and acts like a ban-gee! and wen she plays on the slides with mine and other children she has to go down it first are she will thow a screaming fit it sounds like shes getting hit by a car everyone turns to look and if the kids start to run around a tree or something she screams because the child is a head of her and if shes pickel in the middle with children thowing her toy to one another she freaks out and makes this god for saking crying whining sound i watch dog whisper cezar and he runs across some dogs with similier problems and he touches the dog and it stops well i cant drive and do that at the same time so i get the spray bottle on her but i dont really do it! it kinda snap her out of that frenzy mode that shes in wen i metion spray bottle to her, and i asked other people about the anxiety problem who has dogs and they said that roxy would grow out of it this is the first female dog i ever had and the only one with anxiety issus.i know that this is a behavior problem that has to be address does anyone know of any good books are sites with helping a dog cope with anxiety so i can help her and yes i have asked trainers in my arear of my home but i dont find them in dog training books,it has correcting chewing barking potty training and others but no sloveing anxiety. help please , thanks