I'm sorry to hear about the crappy time you've been having.
I echo a PPs idea of trying to pay the remaining loan off, of possible.
Next, how good are you at meal planning and cooking? If you are reasonably competent, then I have two resources that I would recommend.
On Facebook, or she also has a book, there is "Feed your family for £20 a week". This has an 8 week meal plan, with shopping lists. There is plenty of variety.
At even more of a pinch, but needing a bit more organisation, there is Thrifty Lesley (just search for her website and meal plans). She has about 12 weeks of meal plans, for about £10 for a family of 2 per week. It's pretty easy to alter, to include children.
Even if you used these as a basis, and topped up with a couple of specific things for your DD, plus nappies/household products from Aldi/Lidl, you could be able to save a chunk on your food shopping.
I'd also recommend the free app Olio, which allows people to share food and things for free. Often, it is things that Tesco would throw away at the end of the day, which can safely be frozen. I've got school shoes, a bag of clothes and toys from it, as well as food. It shows these by how close they are to you. I've only got the free version, which works very well.
In terms of birthday/Christmas presents for your DD, I'd also recommend the Christmas bargains threads here. Often, there are excellent, time limited deals on toys posted there. I think we're on the "Bikes are Stollen" thread currently.
Lastly, have a quick explore of if it is worth scrapping your car, or selling for parts on eBay.
Good luck!