My intuition about this situation with her....
The spider bite has had deep effects on her, maybe concerning her energy body. Although it has healed apparently, physically, she still has the lingering effects of the toxin in her system.
She may need energy healing....immune support (I think Immune support tablets for dogs can be bought online. They are not cheap. Del Immune V was one I chose for my dog towards the end of her life. But there will be other options. Make sure if choosing a supplement which was originally designed for humans -that there are no ingredients which are toxic for dogs, or allergenic.
Homeopathic treatment may also help. You could research which remedy to use, based on her symptoms, (which would be the cheaper option) or consult a Homeopathic vet (which would be the more expensive option, but may go more in-depth, and bear in mind the toxins she has been subjected to.
Have you tried "Music to relax dogs" ? (
www.relaxmydog.com) Lovely gentle classical-style music, which apparently has calming effects on dogs.
Another thought....when she was seriously ill, I bet she got a lot more attention. We, as humans (even human children) can understand that they were sick, and so got extra nice things, more love-time, more special treats, etc. But dogs find it hard to join the dots. All they can 'get' is that they were suddenly showered with affection and attention, and suddenly it's not there quite as much anymore. It can sometimes leave them feeling a bit 'lost' and clingy afterwards. They are trying to get that level of attention back again. (?)
Going out to work and leaving a dog alone in the house....we have all had to do it. But it is far from the ideal situation. I've had to do it, in order to earn us the pittance we both needed to pay bills and buy food. I hated every minute. But dogs hate it so much. If they are already feeling peculiar, and then get left alone, they can get strong anxiety. Especially if the ones they are missing are the same ones who showered them with affection and special concern only days/weeks ago.
But of course you have to go out to work. I wonder if it would help if you could hire someone to come in, in the middle of the day and take the dog out for one hour? Sometimes physical exercise to break up the day can smooth out anxiety attacks.
Also, think about playing soothing music for her. Start when you are there, then graduate to leaving it playing when you are out. Start by going out only for short intervals, leaving her alone, (5-10 minutes at first) Then longer times .
When she is actually anxious, don't 'shower her' with anything, including affection -or make any special fuss. Just maintain a calm atmosphere. You can talk gently, but don't look her in the eyes when you do. Just go about your house in that way. Or gently tell her to 'get on her bed and lie down'. (Kindly but firmly in a fairly quiet voice)
If you notice she relaxes (you will have to be observant) -then go to her with a gentle kiss on the head or soothing words, and say 'good girl'. Then carry on as normal -calmly- again.
That's the best I can offer.
But my intuition is going with after-effects of the spider bite. These I believe, deliver neuro-toxins.