Easier just to buy it. There's also no controlling for however many diseases and pathogens you would add to your aquarium doing it yourself. I've never done it before though so let an expert weigh in.
i was thinking buying a pound of live bloodworms, cleaning them and then putting them in freezer bags and then freeze them... do i have to add anything supplements? vitamins? garlic? gellatin?
A lot of nutrients provided with feeding bloodworms and such wouldbe by gut loading the worms. I.E. feeding the worms the things you want the fish to have.
You could also try to soak the bloodworms in whatever nutrients or vitamins thatyou want to give the fish right before you freeze them.