hi Ghost, unfortunately PSD and major depression can never be dusted, once you have had it then it's there forever, however this doesn't mean that somebody can get on with their life and this includes you as well, but we have to learn what our trigger points are that can cause us to once again fall back into this illness.
Please take a step back for the moment, don't be angry with yourself, because if you are then you are struggling with too much on your plate, try the exercises that have been suggested, or you may find yourself relaxing in other ways, I used to love painting our outside window frames to relax me, or take my mind away from being depressed.
Remember that you can't all of a sudden be happy, however if people come to visit you, have lunch, a few drinks then you can laugh, but as soon as they go, back you may fall.
Just try and explain to your friend that you've been going through a patch that has affected me as well as your family, you're not sure how they will react, they may decide to listen and then go away, not to be seen again, but a true friend will stick by you all the way through, in other words they will be there everytime you need them.
They can talk to your family, suggest to them to seek help as well, which is not what my family did, and I also put them through hell, but now everything is great, just take your time, you can't rush through any depression, it's like being able to walk up steps, you gain 2 steps but then you may fall down 1 step, but that's a lesson that you have learned. Geoff.