I have a 11 week old husky but idk whats wrong with him he doesnt want to eat and also he vomited last week and he seems sad all the time now ,, help ?

Vet now.

Not eating, vomiting, low energy, these are potential signs of serious problems, especially in puppies.

Honestly, we don't have much info to go on here as you weren't too descriptive.
You say he doesn't want to eat. At all? How much does he eat in a day?
He vomited last week and appetite has been low since?
How are bowel movements?
Is he tender in the stomach area?

Could be that he ate something that is causing a blockage (a squeaker from a toy, a bunch of fluff from a stuffed toy, a sock, etc).
These could also be from an illness. Has your dog had all it's shots? Has it been around other dogs before getting all it's shots? Was it in areas that other dogs may have been? It may be that it wasn't fully vaccinated and picked up an illness.

If the symptoms are as serious as you make them out to be, you need to get him to a vet.

I agree with Dave, an 11 week old pup has not been fully vaccinated, and it is recommended to wait 4 weeks after the last set of shots to go anywhere where other dogs have been. Once you have gone to the vet we would love to help you on food and nutrition. What food are you feeding? where abouts are you located, that would help as well, it is hard to recommend anything that is found in the US if you live in a different country.

Dayanna as Dave said, the information you've given us is tantamount to saying "My car won't start.", we don't know whether it's out of gas, has a dead battery or even if you have the keys.

Renee suggests the question but where does he stand on shots? Is he around any other animals that might be carrying something - the reason for keeping them isolated until they complete their shots.

Help us help you, please.

well he threw up last week but when he trew up after the third time he threw up a small piece of a plastic bag . which i think was the reason for him throwing up. and well before throwing up he has ate his full bowl of food like normally. i feed him 3 times a day . but after that he wont eat but only once or twice. he will now eat just half of what he used to eat . and well im not saying hes down like he wont move from one place but he was normally very hyperactive and well now hes not as much . i have to look for him and catch his attention for him to want to play or do anything. he has had 7 of his shots and has been wormed twice .. he hasnt been around much dogs because i was told to keep him isolated. only 3 times hes been near other dogs but its when ive taken him out to the park to play i feel bad having him only in the house. i didnt think it would harm him. i feed him purina puppy chow. thats what the breeder that i got him from recommended me but now he seems to not like it so in the pet store i was recomemded a can of the wilderness puppy food i give himt he chicken and turkey flavor. i try to give him apples because he would like them but now he wont eat them . i saw online they are very picky . one day he likes a food the next day he wont. but im unsure...... does this information help out ?

Dayanna, as Dave said, it's time for an immediate vet visit.  When you said that he threw up a small piece of plastic bag that strongly suggests that his intestinal tract is blocked.  That, along with all the other symptoms, point to an immediate need of vet care.

Definitely need a vet visit. Putting it off could result in a huge vet bill or a dead puppy. Neither of which you want.

Today he has ate very good all 3 times and hes starting to be like before . This is a good sign right ?

It is a good sign, but you're not off the hook yet.
By the symptoms and the sudden recovery, a blockage sounds like the most reasonable issue at hand. But unless you've found something in his waste material, you may still have an issue. The blockage material may still be in his system and may get lodged again.
If you see any downturns in activity or eating, get to the vet immediately.

yeah when i got home yesterday he had pooped out a little piece of what he had ate. i mean if he is supposed to go get the rest of his shots on monday im just waiting to see. cause hes playful and cheerful like before again . but ill have the vet check him the day of his shots