For the environment,use ozone shock treatment. It will get rid of the mites in mattresses and everything else.
Ozone shock treatment won't affect paint. The smell will go away in about 30 min after opening windows (O3 turns to O2 quickly). However, it will damage rubber (e.g. rubber bands). Before treatment, it is a good idea to cover expensive items (e.g. laptop) with plastic material. Make sure you are not inside the room when the ozone machine is on (hold your breath when turning off the machine and opening windows).
"these mites have turned my family's lives upside down": I know what it is like. You must get rid of them in the environment first. Otherwise, body treatment won't be effective because of reinfection.
Do you have any idea how the mites came to your home? When did you first notice home infestation?