twitches nerve disorder???

Hiya, my names kayla im 19 years old, been like this for a while now and just wondering if anybody can help me as im starting to
get concearned.....

My symptoms;

Muscle cramps, twiches (mainly in my feet, ankles, fingers, wrists, eyes, mouth, stomache, legs, arms and my back.
I cant really explain the twitches in my stomache and legs and that they get worse when im nervous, my stomach is like
have to push my ribs out or push my stomach right out, my back its like i have to randomly stretch them but it hurts
i cant walk for more than 200metres without struggling to breathe or tight chest pains, i am not over weight or unfit i am a size 10 weighing 9 stone.
I also cant walk without my back locking or getting these twitches and finding it hard to breathe.
Its ok when im sitting down but i still get twitches in my feet, wrists,legs and arms.
I do suffer from aniexty but the pains in my chest are completley different its like the nerves in my body.
Im constantly tires do suffer from terrible abdominal pains and bloating also constipation im not sure wether thats down to me having
Hashimotos thyroiditis (worse form of underactive thryoid), i am also amnemic.
I am also very hormonal.
Ive reasearched the internet to see what it could be the only thing ive found close to what i seem to have is
neuromuscular system disorder.
I have been to my doctor over the past 6months and they keep fobbing me off saying i have acidity, its aniexty/stress
its much worse than that and its really worrying me as my body just seems to be becoming weak and painful
If anybody suffers from this or anything similar could you get back to me thanks.

not sure if i posted this twice?