Hi, sorry for late reply hope you reead thi,
I have been in a very similar situation for 4 years. doctors were baffled and could not halp me. However i finally found out that I have hypothyroidism (despite the blood test being ok) and adrenal fatigue. there is another forum on this site that is dedicated to adrenal fatigue which is really really helpful. I suggest you do a bit of research into adrenal fatigue as vertigo is linked to adrenal misfunction. i have come to believe hormones rule our lives and alter the way we think, so maybe that why you have been depressed ?
hope you find this helpful,
I have suffered from very similar symptoms and finally found out what was wrong with me and im a lot lot better now. now i need to get %100.