I am sorry to hear life is so stressful for you at the moment with potential job changes, especially as you have a history of suffering with low mood and depression.
With this is mind, I wonder if it may be helpful to speak to your GP, if you have not done so already, about extra support that may be available?
If you prefer to follow a natural route you could consider taking Hyperiforce tablets (St John's Wort) which are used to treat symptoms of low mood and mild anxiety.
You need to allow 4-6 weeks to feel the benefit and this may also improve your sleep patterns. St John's Wort is contraindicated with a variety of medication so it is important to refer to the patient information leaflet and your GP if you are unsure whether or not it would suit you.
You could also try Confidence Essence which can help emotionally, during times of stress to address problems with low confidence from both the past and the present.
If the symptoms of low mood, anxiety and low confidence are alleviated to a degree, this may provide extra support through the changes at work.
I do hope things get easier for you very soon.