Did you try Tramadol yet for depression? I've just heard of it for depression. OTC Coedine does help mine a little - I use it maybe once every few weeks.
There are 83 reviews on this link rating Tramadol as 10 out of 10 for depression:
https://www.drugs.com/comments/tramadol/for-depression.html
Here is a forum of other reviews and discussion on the topic (which includes discussion of addiction risk etc):
https://forum.drugs.com/featured-conditions/tramadol-depression-33499.html
I've just heard of it - I am going to try it next, I am just enduring another 5 weeks of depression on St John's Wort, to see if it helps me by week 6. Then I have to wait 2 weeks off St John's Wort, to try Tramadol.
Saying that, I have also just read that the opiate receptors might not be that receptive in people with depression (which might explain how boring I found Heroin when I tried it for the first and only time a few months ago)...but nevertheless, opiates do have hope for Treatment Resistant Depression - this website has a lot of interesting articles on this topic:
https://www.opioids.com/antidepressant/opiates.html