It sounds to me like you've got yourself into a rut and don't know where to start to change things. I've definitely been there.
My DS is just 2 and sometimes watches too much telly too, particularly when I am not well (or for the first 3 months of this pregnancy!). I do have strategies for making sure I get my sofa time though, and these days it isn't all in front of cbeebies!
It must be hard that you get the weekend shift without the lifesaving (for me) toddler groups etc to meet other mums. I think some of the suggestions of things to do sound great, and I'd definitely recommend getting out every day.
My general strategy is to get out in the morning when I have more energy, and to leave the sofa time for the afternoon, preferably when DS is worn out.
As for feeling a bit out of control, can you try changing just thing at a time? With DS the key seems to be repetition, and he responds well to the things I manage to be consistent about. He never tidies his lego, but he loves jigsaws and after we lost bits of a few, I started to be very strict about putting one puzzle away before starting another, and now he (mostly) does it voluntarily!
I think a lot of kids would react badly to having their routine changed so much, so I would start dropping the tv time a bit at a time - just start with 10 or 15 minutes at a time to do something together (once you've got home and had a bit of a relax!) and when you're both more comfortable, add more stuff together.
Our favourite activities are :
- drawing (preferably on huge paper, or scribbling on cbeebies characters printed out from the website)
- singing - we have a few cds from his music class and a box of instruments, and can kill a good 20 minutes singing along and playing different instruments, but I don't have to move off the floor/sofa!
- playdo. I sit DS up at the table and can do stuff on my laptop next to him, while helping him with cutters etc every so often.
- puzzles (mostly jigsaws), lots of which we have picked up in charity shops
- Lego/cars/trains. If I sit with DS doing my own thing, he'll generally play well with minimal assistance, if I try to sit elsewhere or do something in another room, he'll be chasing me around and asking me to join in!
We occasionally do something more adventurous like painting and baking, but I'd definitely work up to them
I've been weaning my DS off his constant TV (from before Xmas when I was both unwell and first-trimester exhausted) We get through a good long afternoon with little TV by interspersing TV time with activities, to the point where he will now play on his own for long periods, with just a few minutes here and there for me to get something out for him or help him draw a shape.
I hope this helps. Please don't feel like you're a shit mother - your DD will appreciate any time you spend doing stuff with her, and I bet you'll find you both communicate better too.