I think my dog is going to die

I'm going to be totally honest. My dog is unwell and I can't afford a vet. I don't mean I don't want to spend the money. I mean I really don't have it. My lovely 2 year old labrador is vomiting daily, refusing to eat and has become very listless. She was absolutely fine - full of life and energy and happy as anything - then suddenly two days ago she went very quiet, started shedding more than usual and started vomiting. We have been travelling long distance with her in the car with us. She has been taken very good care of, and I don't know what has caused her sudden change in health. She is up to date with all her vaccinations, pet passport, and rabies shots etc. She is regularly wormed and flead. We have been washing her every week - which we didn't use to do but with travelling we can't have her bringing lots of mud, leaves and whatever she rolls in in the car. We were in Albania and I got her the contraceptive injection there. Then we were in Croatia and she was running about eating everything - walnuts, apples etc. Then we were in Austria and I noticed some deer ticks in the grass so I didn't let her out again - she was only out for about 10 minutes. Then we were in Northern France and I saw a tiny baby scorpion and threw it out of the house. She was still fine at this point. She was left outside to sleep for one night which I was dubious about but my husband thought she would be fine as the weather was warm. She was getting attention from another big, ten year old male labrador but he had been castrated so I don't think that was a problem. The next morning she seemed fine, but in the afternoon she suddenly became different and has been unwell ever since. I don't know what is wrong with her. I won't have the money for a vet for another week at least. Is there anything I can do for her? I'm so worried.