Hi NowhereUSA, I'm sorry for the way you're feeling and as for the people who made you feel terrible about having depression well......I would say that either they didn't really understand what you were going through or they should have no place in your life.
But well done on reaching out for professional help despite what you must have been going through!! And in persevering with the help for so long.
But bear in mind it has been five to six years you've been working on it. I'm sure that seems a long time but with a yearish (?) or more (?) of that being pregnant (which can sometimes increase depression), having a traumatic labour and like you've said maybe PPD it does shrink down the time scale a little. So don't give up on yourself that easy, OK?
Sometimes therapy can be a longish process, it'll vary according to the individual. Sure some people may take six months but for others it can take longer. It wouldn't harm to ask your T about anything else they can recommend though, either in them using different approaches or things other than DBT you could try. And maybe even some support groups, particularly if you have PPD. Sometimes it can help in sharing your experiences with others going through it and sharing ideas and support.
As for the medication though........I wouldn't necessarily give up hope, sure sometimes there are cases when no medication will make a difference, but sometimes (as there are so many out there) it can be hitting on one specific one or an exact combination which is going to work for you. Sometimes it can be about hitting on the right combination and dosage of three...four....medications. So still some possibilities out there, right??
And even if nothings feeling better next week.......next month........two months from now........then you know at least in/over that time there are people here as well who can relate to how you feel, give you understanding, empathy, support in what you're going through. And sometimes just talking, letting it out can sometimes help a bit.......so don't hesitate in telling us about how things are for you. We're here.
And welcome to PC!!!
Alison