The finances and the guilt.
My mum and sister were amazing, between them they filled the role of the other parent, attending things when I couldn't because I had to work, both were working/studying ft so I also relied heavily on nursery and friends sometimes - the guilt of having her pushed from pillar to post so I could work two jobs was immense, I felt guilty either way, if I took more time and had less money, or if I worked every second I still felt guilty. I guess it was being in that no win situation and having to balance it somehow, because there was very little input of time or money from her father to balance it out.
The upside to that is she never struggled with going to school or nursery, I never had the clinging and crying some people do, she was always happy to go in, or to nanny's or aunty without any bother, and she's now very independent and has an amazing relationship with both of them.
I guess the small things stick in my mind, like having to take the decision not to tell her she was going to her dad's until (if!) He turned up because I couldn't bear her disappointed little face and the sadness from her when he let her down, and there was nothing I could do about it.
Or saying no to a magazine because I couldn't afford it, or having to leave her with my mum when she was unwell because I couldn't take time off work without risking my job.
Mine is an adult now, and I'm incredibly proud of who she is and although it was so hard sometimes, it was definitely worth it.
It does and will get easier, gradually and day by day, until one day you realise you're where I am now - then you start wondering what the hell you're going to do with yourself now!