I genuinely believe 'puppy blues' are a real thing. 
It sounds like he's not quite sure what the routine is yet and he's trying to work out the boundaries. Do you have him sleeping in your room? If so, nip that in the bud now and he sleeps in the kitchen from now on. By having access to you 24/7 he's not learning to be alone, hence why you're having separation issues. Use a crate if you can, if you don't have one already you need to introduce it very very carefully so that being in his crate is a positive experience for him. Feed him in there, play with him in there etc. Loads of advice online on how to do this properly. DO NOT just put him in the crate on day one, it will scupper your chances of a gradual introduction.
THe crate will allow you to tackle the none sleeping. Pups can hold their bladder for an hour for every month of life, so at 15 weeks (when you'll be able to use the crate) he can hold it for about 4 hours. Once the crate is introduced properly, crate the pup overnight and set your alarm for 4 hours time. Let pup out for a wee then everyone goes back to bed. Do not go down to him other than the 4 hour window unless he's displaying behaviour that's very distressed. By this point though, you should have introduced the crate in such a way that being in it is safe, warm and happy for him so he'll sleep.
I can't recommend absolutely knackering out the little bugger highly enough 
. Get him absolutely pooped just before bed and get the rest of the family to help. This can be walks, training, play, even mind games like snuffle mats or treat balls. It might seem like he's got nothing but energy but puppies crash out easily, so time your walks and play sessions for pre-bedtime.
Do you have recall with him yet? If not, get yourself a long line. NOT a retractable lead, an actual 50ft long line. Horse lunge ropes are good for this. Get to your nearest field and just let him explore/ run/ bark/ let off steam. Do this at least 3 times a day for now (one just before bed) for 30 mins at a time in addition to his regular walks. While you're there work on recall. More than anything, freedom to roam safely will tire him out.
Next, do you have much time to play/ interact with him while you're watching him during the day? If so, I suggest working on bits of obedience training. Pups are never too young to learn basic commands and it will help foster the bond between you. There's loads of Youtube videos on how to teach commands and they're fab. The basics I'd work on with him are:
Sit
Wait in Sit
Down
Wait in Down
On lead heel
off lead heel
RECALL!!!
Do 10 minutes at a time a couple of times an hour. get one perfected before moving on to the next command and make sure you do each command you've already learned a couple of times a day too. Use either food treats (sacrifice a bit of his normal diet for training) or play with a toy, depending on what motivates him more.
Lastly, what food are you giving him? Some foods are more energy dense than others and the higher the fillers in it, the more hyper your pup will be. You need him on a very good quality food to limit his hyperactivity. Expensive DOES NOT mean high quality. You want something where the first 3 ingredients on the back are meats NOT meat and animal derivatives etc. If the first 3 are not meats, then you need the first 1 or 2 to be meats and for them to combine to make up at least 60% of the overall formula. Anything less than this is not a good food and will be making the problem a lot worse.
You get out of a dog what you put in and at the moment you are in a really great position in that you've got time to invest in your boy. I promise you that if you put the owrk in now, your pup will repay you a million times over by becoming a well adjusted, super happy member of the family.
Also always remember: dogs can't do things to spite you or annoy you purposely. Bad behaviour comes from misunderstanding the rules, they are never ever bad on purpose. It sounds daft, but during the puppy days just remembering that was massively helpful to me!