Must following you in are there standing water around where you are you can get stuff that kills there larvee in water .
Wish you had dragonflys they eat lots of them in all stage's of life.
They do make things that you wear that sound like dragonfly's wing's scares them away.
Only other thing mosquitoes net by front door or a fogger to kill them and a type of candle they hate.
Google mosquitoes control.
I don't have anything for preventing bites, other than becoming a ninja and killing them before they can bite you (I've done it with drum sticks before). But as for relieving itchiness, use an alcohol swab on the afflicted area (most baby wipes work too) as soon as you're bit.
They may be coming in through a vent. Do you have a fireplace because they'll come in that way. You should buy a four poster bed and some mosquito netting. Then they wouldn't be able to bite you while you sleep. My family has a cabin in the woods in northern Toronto and the mosquitoes are fierce up there during the summer. You have to enter a door very quickly because they'll follow you in.