Poor you, you do sound really down. Hope your gp can give you the support you need. In the meantime, are there any adults around in rl that can help you out? I am sure a Mumsnetter in your area would be willing to come and assist if you ask for help.
A couple of practical things that might help:
Flylady crisis clean instructions here
(Ignore barftastic language - underlying principles are sound)
buy a timer and start just doing 5, 10 and 15 min of focused effort on firstly (a) throwing rubbish away (b) picking up dirty clothes (c) tidying up and putting things away. It's amazing what difference even 5 mins of concerted effort can do.
You can't clean clutter so stop wasting your energy on it and get rid.
Do one load of laundry from beginning to end, ie drying and putting away, every day.
Ask a friend (or local Mumsnetter) to come and help for a couple of hours say for two mornings a week.
And most important of all I reckon: ring-fence the time when you clean and the time when you stop and do something more interesting/play with your dd otherwise it's all too groundhog day ...
And ring-fence at least one or two hours per week just yourself to do something that you really enjoy.
Finally, if you want to join us on the (Flylady) Fledglings thread here here you would be really, really welcome. It looks cliquey because loads of us have been on it for years, but it is really friendly. We are not posting Flylady links at the moment during the summer, but will start again in September. The links provide you with daily steps and routines to get back on top of the housework. It might be worth decluttering in July and August and starting Flylady baby-steps (1-31) in September.
Good luck with it all anyway, however you decide to tackle it. But definitely would recommend a trip to the GP first. Ban negative thoughts and guilt and priortise your own needs for once. Then, once you are feeling better, you will have some energy to expend on your house.
Take it steady. Be realistic. Your house didn't get like that in a day. It will take time to get it back under control. But you can do it!!