I'm sorry I've been offline for a while - cried most of the afternoon and slept when I wasn't crying. And, as per usual, once my daughter was in bed, I went back to crying again 
I'm so very grateful to all of you for your touching responses. I wish I could see things as clearly as you.
Perhaps I should explain - my mum passed away back in 2010. My partner didn't leave as a result of this; I wasn't actually with him at that time. He left because I found out he had cheated on me with his ex-wife. I guess she was a more exciting prospect than me, and how can I compete with the mother of his children?
The psychiatrist assessment I am supposed to get organised is so that I can go ahead with counselling covered by my private medical cover. So far my GP has given me the name of the psychiatrist for my insurance company to arrange an appointment with, so wheels are in motion.
What I'm having trouble with is moving things along because I have such low self-esteem at the moment that I don't believe I'll conquer this feeling of utter loneliness and failure. I failed at my marriage pretty much from the outset. The only good thing to come out of it was my daughter. I was left to bring her up on my own when she was just three months old, and from that moment on, I felt an absolute failure as all the other new mums I knew had their partners around. At least during that time I could call my mum for reassurance that I'd be okay.
My ex-husband eventually faced his responsibilities and started being a part of our daughter's life. He now sees her on a regular basis and she spends every other weekend at his house.
My next partner was around at the times of both my parents' deaths and tried to be supportive, but he left me the day after I was burgled and all my mum's jewellery was stolen (ironically a year to the day she had died).
I hooked up with the partner who's been cheating on me a few months afterwards. He was an old school friend and what started out as friendship and support for me turned into a serious relationship. He'd even recently been talking about me moving in with him. Having had a disastrous 2009 and 2010 dealing with my parents' deaths, I was beginning to think things were looking up for the end of 2011 and beyond. Then, on New Year's Eve afternoon, I found out about the cheating.
I haven't had the courage to tell my daughter that "he" won't be around any more. She'll be gutted as she not only got on with him but was very fond of his kids (just a bit younger than her do she treated them like siblings). So I feel like I've let her down too 
Christmas is always a rough time without my mum as she'd usually be spending time with us, but I can't handle her not being here now more than ever.
I'm like Midas - with the difference being everything I touch turns to sh*t 
