Cocker spaniel anxiety extreme

Question
My 3 year old cocker Lil Girl has extreme anxiety. For starters she has always had this problem when she gets excited in a good or bad way, she starts wailing like a fire truck, intermttently yelping as if someone is killing her. When this happens we say no or try to comfort her or as of lately just put her outside until the behavior ceases. That has been since day one. Just lately she has begun doing that every few minutes for hours on end, cowering, digging a hole by the gate ( she never has done this ever) and laying in, turning in circle in a very agitated way while yelping. If i throw her ball the behavior ceases temp. if i shower her with affection the behavior ceases, so i do not believe it is a physical condition but rather emotional. She tried to bite me when i went to touch her last night and refused to move from the bed...we do not let her rule our bed at all, so this is very odd. She also incessintly will lick at her back legs and belly, she is not in heat, but has not been fixed yet. Upon inspection there is nothing there, fleas, wounds, skin cond. , etc. When we introduce physical activity she does not appear to be in any pain whatsoever in the leg area and is generally happy. She is extremly non social with other dogs despite beiing exposed to them since she was 16 weeks old. I have a 9 month old baby who just began crawling and i feel it is directly related to that. I fear for her saftey and my childrens saftey. She has alway been nervous, but she is having a full blown doggie nervous breakdown.When i approaxh her while she cowers on the side of the gate under some brush, she looks almost aggressive and i am afraid to go further. When i call her to come in the house, when its nice and quiet inside, she runs to and fro then goes back outside and yelps, laying down. She cannot be distracted by treats, toys or anything. Although she seems to want to. Help me please.

Answer
Sounds like in the beginning you gave her a lot of mixed signals.
It's totally natural to want to comfort a dog who's anxious.  But, in fact, it's exactly the wrong thing to do.

There's a lot here - but I'd like you to try something first.
Get one of those leashes (Petsmart) that goes around your waist instead of the usual hand held type.  Attach her to you...no conversation at ALL...where you go, she goes.  Keep it up as long as you can...but do not coax, chat, command, or anything.

I'd like to know how she reacts.  The leash is a powerful tool for both anxious dogs and aggressive dogs.

And where does she sleep?  And why isn't she spayed?