I don't think I'll ever sleep properly again.

I can't stand this, I wish I had weaned DD a long time ago. I've had success with no boobies during the day, only one to go to sleep. But that ONE turns into 15, she keeps demanding boobs over and over again at nightime. If she wakes at night "boobies, need you mum, boobies". So this is usually 2x a night.
I've got Mitch waking once to go to the toilet, sometimes another time with a bad dream. I start dinner, bed, bath at 5.30pm every night to get the plenty of time to settle. I've been doing the SAME routine, verbatim every single night for at least a YEAR.
What does my head in the most is that sometimes it works and sometimes it doesn't and when it doesn't I'm stuffed for the rest of the night. 2 weeks ago, DD was going to sleep fine, minimal yelling (2-3mins), maybe waking about 3 for a quick boob then back to sleep in bed with me (its bluddy COLD here).

Last night

5.30 Dinner
6.00 Bath, jarmies quiet play
6.30 Supper, small snack, brush teeth
7.00 Story and bed
8.30 still settling DD
10pm DD wakes yelling again
10.30 give up and go to bed with DD
1am DS wakes for the toilet
3am DS wakes with bad dream and is cold - in bed with me
5am DD wakes for a boob
8am all awake, stumble out of bed and cry from exhaustion

Yes I like being a parent but FFS my youngest is 2 and I thought I would be able to get some decent sleep or even 2 consecutive hours to myself at night.
I'd love some time to myself at night to be able to maybe read, do housework, cook or even STARE AT THE WALL. Sometimes I do get it...sometimes.
What kills me the most is the whole ON/OFF thing, if it was total crap and lack of sleep ALL THE TIME I could cope with that (I think), but I never know whats in store. I can get nothing done.

I have to go back to work and quickly. How the hell will I be able to manage?
I'm tired, my boobs are tired and I just resent the hell out of everything to do with being a parent right now. I don't even care how this sounds I need to get it off my chest.