Shotgun please go and see you doctor about Prozac. It shouldn't have that effect on you. I took some anti-depressant myself, and after a week I could feel the fog lifted. I'm worried and concerned that you have been given something that is doing the opposite of what it should.
For all the financial arrangement and D paperwork, could your sister gives you a hand.? I know it's hard to ask for help, but I reached out to my siblings and they have been of a great support as they were able to provide me with a different view of things. Before I'd have seen asking for help as a weakness but now it's a strength as you are admitting that you are only human, and from time to time you need support.
I also realise how much stress you must be under as our society portrays men as strong, reliable, a rock when everything goes wrong. I think this is wrong as we are all human being, with a heart, emotion and feelings!
You are getting up everyday (that is a plus) , you are spending time with your son (another plus). Sometimes to shift our mind, we need to start small. Try see what can be positive in your day. Feeling the sunshine on your face ( I do hope you get more than I do a cross the Atlantic:-)), give a hug to your kid, speak to him on the phone.
Mind is a powerful tool that can destroy us or enrich us, choose the second option. I went through what you are experiencing at the moment, you can get out of it but you need to start small. See the little nice things in your day ( your favourite song, coffee), then you'll train your brain to see the positive.
You have so much to offer, don't let go of who you have become. Nobody said it would be an easy ride, but you can surf the wave or let it drown you, and I know that you are a fighter and that you'd rather surf it than drown.
I know you can do it, and I believe in you. Keep your chin up :-).