I can't leave you unanswered..
Although i was where you are a long time ago, still am really, but i've got used to it..
My first thought was PND, your DD is still very little, have you felt like this since having your DD, or is it mainly due to a crap week/ feeling knackered?
You've made it through another day, and i congratulate you, its really really hard, especially at this time of year too, its not like you can go out for a potter about.
How about trying to find other mums who are alone, is there a Gingerbread in your area? Weekends are soo hard when everyone else is all coupled up.
Can you give yourself something to look forward to, it sounds silly but even things like buying something online and looking forward to its arrival, is something.
Is there anything you can think of to do in the evenings.. being creative in some way? making things can give you a confidence boost and is a great way of taking your mind off things.
Am sending you hugs, you can get through it and it does get easier with time, even though that doesn't really help you at this moment in time.
Keep posting, theres lots of MN lone parents here, even though it's a bit quiet tonight, i'm always around!