don't know what to do! 😩😩

So I broke up with my fiancé just before Christmas, he was controlling etc and I couldn't do it anymore. We were trying to conceive for 2 years! With absolutely nothing, didn't fall pregnant once..we were about to go down the road of all the specialists etc but I ended it
Anyway, fast forward 2 months and 2 weeks ago I had a one night stand..
Back to today..and yep you guessed it, took a pregnancy test as I have been feeling unwell the last week and very different to my usual pms symptoms and I just knew it would be positive!
I already have an almost 7 year old girl..and I've brought her up on my own..
But now I'm confused with this pregnancy! I'm just recently single, and I'm in 2 minds about it!
It's all I've wanted for the past 3 years, is another baby and now it's happened..when I'm single and the dad would want absolutely nothing to do with it..I don't even like him in that way! 😩😩 
I feel horrible, I've had a previous abortion about 4 and a half years ago and I regretted that ever since..but now I feel like it would be the worst time to have a baby but then I still want it!