Friend, when a dog is not willing or losses the ability to stand we need to try to determine if this is the result of a primary neuromuscular disorder or secondary to a systemic disease. For example, a dog with a slipped disc will not have the ability to stand because of the disc compressing the spinal cord. Or, if the dog is systemically like if he/she had: Kidney or liver disease, infections, a tumor, heart disease, etc. they may refused to stand up because they do not feel well. The fact that he vomited I am inclined to believe this could be related to a systemic disease as mentioned above. However, neuromuscular disorders need to be ruled out as well.
In this case unfortunately we are very limited as to what you can do at home. I would strongly recommend having him checked this morning by nearest veterinarian, do not wait. Most of the above mentioned diseases could have a fatal outcome if he is not treated promptly. In addition, if related to a slipped disc the longer he goes untreated the less likely he will recover. Unfortunately not much I can recommend for you to try at home, I am sorry.
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