I woukd seriously be concerned there might be a blockage whether it be some foreign object, tumor, etc. If this has gone on this long, he should be seen by your Vet for an evaluation.
Vomiting daily or even three times a week is NOT normal! And neither is projectile vomiting. Most healthy dogs vomit only occasionally.
You do need to take him to see a vet very soon.
Take a stool sample and vomit sample with you in separate labelled containers.
Greenish-brown fluid with white flecks? Large amounts of it? I have no idea what that could be but he needs a vet to see him. Anything particularly foul-smelling could mean food is laying in the stomach way too long....or could mean intestinal contents are being vomited up! Or....can sometimes mean there is Parvo virus.
It can't hurt, and might help, but I if you aren't now, you might try some 'acidophulis' (aka 'pro biotics'), in case it is an intestinal virus or bacteria. Were he mine, I would give a 25 billion bacteria count twice a day. More effective if capsule contents are mixed with a little room temp milk. Milk helps protect it from stomach acid on it's way to the intestines.
I only buy it from somewhere that keeps it 'refrigerated', not off an open shelf. You should also store it in the fridge. It can be pricey, but still much cheaper than a vet visit or meds.