This problem is more severe than you probably realize. You puppy is in a phase of life than will influence his personality and future behavior more than anything else. If you let him get his will by being aggressive, he will continue doing so as he grows older.
First of all, you must not, under any circumstances, cause him pain or harm. That only teaches him that he must fight harder and more aggressively to gain his goals.
Step 1: understand his body language
I strongly advise you to learn about the body language of dogs and the signs of aggression. Those signs can be as diverse as lifting a paw, yawning, licking his lips in a certain way or avoiding eye contact with something he doesn't like. This is a small collection of Youtube videos I found very informative, but you can find many more of those.
Step 2: identify his triggers
For this you need to understand his body language first. Try noticing changes in his behavior before he starts biting you. I guarantee you that he gives you several signs before that, you just always ignored them because you didn't understand them.
What triggers his aggression? Being touched in a certain way? Having you approach his food or his toys? Wrapping him up in blanket? (I honestly doubt that he likes it. Please try a different way of calming him down.)
Guarding behavior is common in dogs and requires special training. If you suspect your dog is aggressive because he guards his property, please search for "food guarding" or "toy guarding" to learn what to do.
Step 3: train him
You write that you've got the dog 4 weeks ago. He doesn't need "as much rest as possible". He needs walks and play time and obedience training. He needed all that 2 weeks ago already!
Immediately start daily obedience trainings with him. The least you need to teach him is "come", "sit" and "no". Teaching him "stay" greatly improves his character by teaching him that impatience doesn't pay off. Doing "target training" with him, where he needs to touch your hand or another target object, can help in situations where you need him to move a certain way, like at the vet.
Don't make the mistake of thinking obedience training is boring and a hardship for your dog. It feels actually very good for him to be praised by you and it strengthens his bond to you.
His aggression can also be an expression of his boredom and need for exercise. Young puppies - just like children - have an enormous amount of energy and need to burn a big part of it every day. Locking a dog inside and giving him nothing but a half-hour walk and "as much rest as possible" is a surefire way to have a dog that destroys your entire furniture out of boredom. Instead, you should play little games with him a few times each day or let him work for his food by feeding him with a puzzle feeder. Please have a look at this list of ideas.
Step 4: punish his aggression
I'll repeat myself: You must not cause your dog pain or he only learns to bite harder to avoid the pain. If you only employ these methods without offering enough training and play to your dog, you won't really get rid of his aggression. You'll only teach him to hide his warning signs and ambush you instead.
The first thing you should do when you notice his warning sings is to stop doing what you're doing. Your dog clearly tells you that he doesn't like it. If those things he doesn't like are things like being pet, hugged or wrapped in a blanked, you need to accept his wish and stop it.
If that doesn't help, you should cause him negative consequences that are not painful.
A tried method is a water squirting bottle. When your dogs body language exceeds a certain level of aggression, you squirt water at him. Of course this is only practical outsides.
An alternative is putting a few screws, nuts or washers into an empty and dry 0.5 liter bottle and screwing the lid back on. When your dog gets too aggressive, you throw the bottle at the ground close to him, but not directly at him. The rattling of the bottle is a strong acoustic signal and snaps your dog out of the aggression.
