Whats wrong with my dog? :(?

I Have a Boxer puppy ,male the problem with him is that he won't eat. All he does is drink water when he throws up its water plus this white foamy substance. Plus he is drooling a lot and well I don't have money to take him to the vet and I'm extremely worried. I've been hand feeding him to keep him from getting super weak and I've also have given him baby pediatric electrolyte to keep him hidrated. Also some of his stool samples are basically just water no blood whatsoever. But please help I would extremely appreciate it and to those who give really supportive comments I thank you.