Cat keeps getting aggressive and bites

I've had my cat for almost 3 months now. When I first got him he was really playful and tender, but a couple of weeks ago he started getting aggressive. When I walk into a room and he sees me, he makes this weird noise then runs away and hides. He always bites my head,feet,thigh,ear,nose EVERYTHING. Its not just me , he bites my other family members as well. Hes about 5 months and hes a persian breed. 

The thing is, he sleeps on our laps when hes tired, he kneads on us. He used to head butt me, but not so much atm. And My theory is, since his nose is always watery for some reason, maybe he cant smell properly, so hes just biting us? Idk sounds stupid but could be the case. Or it could be the fact that hes sick, or just has gotten used to playing aggressively. Like idk what it is, he doesn't seem to show much affection atm and im worried

Is he neutered?  If not, he might be sexually frustrated.

If he is neutered, has any changes happened recently?  It could be minute to you but cats do not like change.  Also, something may have or is still currently happening that is upsetting him.  Maybe another cat or animal outside marking and being aggressive with him?  Or someone has been too rough with him maybe?

I have Persians and they are prone to watery eyes which need to be cleaned.  I suggest Angel Eyes.  But, it wouldn't necessarily interrupt his smelling process unless he's sick and has a URI.

Thanks for the reply, No he is not neutered.  But I will Consider taking him sometime this month, his eyes are always watering for some reason, the vet never mentioned anything other than that it was caused by scratching his ears from the ear mites he used to have. Minutes ago I attempted to hug him with my arms wide open and he kept running, he also made this weird nose before he ran.

No Persians are prone to watery eyes.  Just keep them clean.  I am concerned that your vet doesn't seem to know cats?  Maybe they just don't know much about the Persian breed?  That could be it.  The watery eyes are actually just normal but if it gets "goopy" a lot, it is caused by a form of herpes.  Don't worry, you can't get it!  And it doesn't really harm your cat, you just need to make sure to keep them clean.  Just some water will do the trick.

He might be in pain?  Cats often become grumpy and aggressive when sick or in pain.  So if you can, schedule a vet visit to look him over again.