Rescue Staffie cross

[Anna Mg]

Hi - first day on here and need some help! My dog belle is 4.5 and we have had her 5 months. She is partially sighted and ball possesive. I also think she is quite a nervous dog - probably because of the sight/re-homing!

During week 1 with her i had her loff lead in the dog park and another staffie owner threw her ball for her dog. Belle had hers in her mouth but still runs after balls. The other dog thought she was going to take it and bit her at the top of her leg. Belle then bit her back lower down the leg and they were locked on - tried to pull apart but in the end other owner hit my dog with the ball thrower and she stopped.

Due to this i now have a terrible fear of letting her off around other dogs in case they have a go at her and she bits or they just rub her up the wrong way and it gets out of control really quickly - this incident happened in a heartbeat. I really want to gain some confidence here but not sure how. I let her meet other dogs on lead but i would say 50% of dogs either bark at her, lie down or are aggressive. Usually she is pretty indifferent to them but i am sure she is giving off something to make them react??? Any ideas

She never mouths and is the kindest most friendly dog with humans. She plays with soft toys and jumps all over them but never bites or rips them.

Does anyone recognise this behaviour, why do some dogs react really badly to her? She is quite hyper and i have not found a way to calm her down yet so could this be it??

Sorry for all the questions i just would like to start correcting some of these things if i can!!

Thank you