we adopted a blacklab mix a few years ago, he's been very healthy up until this point. (I should note that Tobe has a stomach of steal, he will eat anything that he can swallow if you aren't watching him.) Thursday night before his dinner he threw up, we feed him later on, he kept it down. Friday morning he threw up his breakfast, he was still acting like normal crazy tobe at this point. After the park (we left early because he was asking weird) he threw up on the sidewalk, 20 mins later he threw up again. at this point he started asking very tired, uneasy, seems uncomfortable and he's been laying in weird spots. He threw up 2 more times. Saturday he didn't move all day, won't eat anything and was drinking a little bit of water. He started shaking at some point yesterday evening. Today, he seems more active, still very slow, sleepy and sleeping in weird places. But he still wont eat, I tried giving him pizza (just to get him to eat) he put it in his mouth but spit it out. he begging for food but won't eat it.
here the problem, i have no money to take him to the vet, I'm on a very low income. There aren't any vet schools in our area, I'm nervous that if I take him to the spca they might take him away. How long should we stick this out before we take him to the vet? are there any home cures?
please help

Optional Information:
Age: 4; Male; Breed: blacklab mix

Already Tried:
keeping water available, tried giving him rice, dogfood and pizza./p>